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Made available in DSpace on 2021-06-25T11:16:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Agence Nationale Des Parcs Nationaux Centre for International Forestry Research Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS) David and Lucile Packard Foundation European Space Agency Leverhulme Trust Gordon and Betty Moore Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado de Goiás European Research Council Belgian Federal Science Policy Office Vlaamse Interuniversitaire Raad Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) National Science Foundation Natural Environment Research Council Royal Society National Geographic Society Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of funding agencies. Here we show how a global community is responding to the challenges of tropical ecosystem research with diverse teams measuring forests tree-by-tree in thousands of long-term plots. We review the major scientific discoveries of this work and show how this process is changing tropical forest science. Our core approach involves linking long-term grassroots initiatives with standardized protocols and data management to generate robust scaled-up results. By connecting tropical researchers and elevating their status, our Social Research Network model recognises the key role of the data originator in scientific discovery. Conceived in 1999 with RAINFOR (South America), our permanent plot networks have been adapted to Africa (AfriTRON) and Southeast Asia (T-FORCES) and widely emulated worldwide. Now these multiple initiatives are integrated via ForestPlots.net cyber-infrastructure, linking colleagues from 54 countries across 24 plot networks. Collectively these are transforming understanding of tropical forests and their biospheric role. Together we have discovered how, where and why forest carbon and biodiversity are responding to climate change, and how they feedback on it. This long-term pan-tropical collaboration has revealed a large long-term carbon sink and its trends, as well as making clear which drivers are most important, which forest processes are affected, where they are changing, what the lags are, and the likely future responses of tropical forests as the climate continues to change. By leveraging a remarkably old technology, plot networks are sparking a very modern revolution in tropical forest science. In the future, humanity can benefit greatly by nurturing the grassroots communities now collectively capable of generating unique, long-term understanding of Earth's most precious forests. Resumen: Los bosques tropicales son los ecosistemas más diversos y productivos del mundo y entender su funcionamiento es crítico para nuestro futuro colectivo. Sin embargo, hasta hace muy poco, los esfuerzos para medirlos y monitorearlos han estado muy desconectados. El trabajo en redes es esencial para descubrir las respuestas a preguntas que trascienden las fronteras y los plazos de las agencias de financiamiento. Aquí mostramos cómo una comunidad global está respondiendo a los desafíos de la investigación en ecosistemas tropicales a través de diversos equipos realizando mediciones árbol por árbol en miles de parcelas permanentes de largo plazo. Revisamos los descubrimientos más importantes de este trabajo y discutimos cómo este proceso está cambiando la ciencia relacionada a los bosques tropicales. El enfoque central de nuestro esfuerzo implica la conexión de iniciativas locales de largo plazo con protocolos estandarizados y manejo de datos para producir resultados que se puedan trasladar a múltiples escalas. Conectando investigadores tropicales, elevando su posición y estatus, nuestro modelo de Red Social de Investigación reconoce el rol fundamental que tienen, para el descubrimiento científico, quienes generan o producen los datos. Concebida en 1999 con RAINFOR (Suramérica), nuestras redes de parcelas permanentes han sido adaptadas en África (AfriTRON) y el sureste asiático (T-FORCES) y ampliamente replicadas en el mundo. Actualmente todas estas iniciativas están integradas a través de la ciber-infraestructura de ForestPlots.net, conectando colegas de 54 países en 24 redes diferentes de parcelas. Colectivamente, estas redes están transformando nuestro conocimiento sobre los bosques tropicales y el rol de éstos en la biósfera. Juntos hemos descubierto cómo, dónde y porqué el carbono y la biodiversidad de los bosques tropicales está respondiendo al cambio climático y cómo se retroalimentan. Esta colaboración pan-tropical de largo plazo ha expuesto un gran sumidero de carbono y sus tendencias, mostrando claramente cuáles son los factores más importantes, qué procesos se ven afectados, dónde ocurren los cambios, los tiempos de reacción y las probables respuestas futuras mientras el clima continúa cambiando. Apalancando lo que realmente es una tecnología antigua, las redes de parcelas están generando una verdadera y moderna revolución en la ciencia tropical. En el futuro, la humanidad puede beneficiarse enormemente si se nutren y cultivan comunidades de investigadores de base, actualmente con la capacidad de generar información única y de largo plazo para entender los que probablemente son los bosques más preciados de la tierra. Resumo: Florestas tropicais são os ecossistemas mais diversos e produtivos da Terra. Embora uma boa compreensão destas florestas seja crucial para o nosso futuro coletivo, até muito recentemente os esforços de medições e monitoramento foram amplamente desconexos. É essencial formarmos redes para obtermos respostas que transcendem fronteiras e horizontes de agências financiadoras. Neste estudo nós mostramos como uma comunidade global está respondendo aos desafios da pesquisa de ecossistemas tropicais, com equipes diversas medindo florestas, árvore por árvore, em milhares de parcelas monitoradas à longo prazo. Nós revisamos as maiores descobertas científicas deste trabalho, e mostramos também como este processo está mudando a ciência de florestas tropicais. Nossa abordagem principal envolve unir iniciativas de base a protocolos padronizados e gerenciamento de dados a fim de gerar resultados robustos em escalas ampliadas. Ao conectar pesquisadores tropicais e elevar seus status, nosso modelo de Rede de Pesquisa Social reconhece o papel-chave do produtor dos dados na descoberta científica. Concebida em 1999 com o RAINFOR (América do Sul), nossa rede de parcelas permanentes foi adaptada para África (AfriTRON) e Sudeste asiático (T-FORCES), e tem sido extensamente reproduzida em todo o mundo. Agora estas múltiplas iniciativas estão integradas através de uma infraestrutura cibernética do ForestPlots.net, conectando colegas de 54 países de 24 redes de parcelas. Estas iniciativas estão transformando coletivamente o entendimento das florestas tropicais e seus papéis na biosfera. Juntos nós descobrimos como, onde e por que o carbono e a biodiversidade da floresta estão respondendo às mudanças climáticas, e seus efeitos de retroalimentação. Esta duradoura colaboração pantropical revelou um grande sumidouro de carbono persistente e suas tendências, assim como tem evidenciado quais direcionadores são mais importantes, quais processos florestais são mais afetados, onde eles estão mudando, seus atrasos no tempo de resposta, e as prováveis respostas das florestas tropicais conforme o clima continua a mudar. Dessa forma, aproveitando uma notável tecnologia antiga, redes de parcelas acendem faíscas de uma moderna revolução na ciência das florestas tropicais. No futuro a humanidade pode se beneficiar incentivando estas comunidades basais que agora são coletivamente capazes de gerar conhecimentos únicos e duradouros sobre as florestas mais preciosas da Terra. Résume: Les forêts tropicales sont les écosystèmes les plus diversifiés et les plus productifs de la planète. Si une meilleure compréhension de ces forêts est essentielle pour notre avenir collectif, jusqu'à tout récemment, les efforts déployés pour les mesurer et les surveiller ont été largement déconnectés. La mise en réseau est essentielle pour découvrir les réponses à des questions qui dépassent les frontières et les horizons des organismes de financement. Nous montrons ici comment une communauté mondiale relève les défis de la recherche sur les écosystèmes tropicaux avec diverses équipes qui mesurent les forêts arbre après arbre dans de milliers de parcelles permanentes. Nous passons en revue les principales découvertes scientifiques de ces travaux et montrons comment ce processus modifie la science des forêts tropicales. Notre approche principale consiste à relier les initiatives de base à long terme à des protocoles standardisés et une gestion de données afin de générer des résultats solides à grande échelle. En reliant les chercheurs tropicaux et en élevant leur statut, notre modèle de réseau de recherche sociale reconnaît le rôle clé de l'auteur des données dans la découverte scientifique. Conçus en 1999 avec RAINFOR (Amérique du Sud), nos réseaux de parcelles permanentes ont été adaptés à l'Afrique (AfriTRON) et à l'Asie du Sud-Est (T-FORCES) et largement imités dans le monde entier. Ces multiples initiatives sont désormais intégrées via l'infrastructure ForestPlots.net, qui relie des collègues de 54 pays à travers 24 réseaux de parcelles. Ensemble, elles transforment la compréhension des forêts tropicales et de leur rôle biosphérique. Ensemble, nous avons découvert comment, où et pourquoi le carbone forestier et la biodiversité réagissent au changement climatique, et comment ils y réagissent. Cette collaboration pan-tropicale à long terme a révélé un important puits de carbone à long terme et ses tendances, tout en mettant en évidence les facteurs les plus importants, les processus forestiers qui sont affectés, les endroits où ils changent, les décalages et les réactions futures probables des forêts tropicales à mesure que le climat continue de changer. En tirant parti d'une technologie remarquablement ancienne, les réseaux de parcelles déclenchent une révolution très moderne dans la science des forêts tropicales. À l'avenir, l'humanité pourra grandement bénéficier du soutien des communautés de base qui sont maintenant collectivement capables de générer une compréhension unique et à long terme des forêts les plus précieuses de la Terre. Abstrak: Hutan tropika adalah di antara ekosistem yang paling produktif dan mempunyai kepelbagaian biodiversiti yang tinggi di seluruh dunia. Walaupun pemahaman mengenai hutan tropika amat penting untuk masa depan kita, usaha-usaha untuk mengkaji dan mengawas hutah-hutan tersebut baru sekarang menjadi lebih diperhubungkan. Perangkaian adalah sangat penting untuk mencari jawapan kepada soalan-soalan yang menjangkaui sempadan dan batasan agensi pendanaan. Di sini kami menunjukkan bagaimana sebuah komuniti global bertindak balas terhadap cabaran penyelidikan ekosistem tropika melalui penglibatan pelbagai kumpulan yang mengukur hutan secara pokok demi pokok dalam beribu-ribu plot jangka panjang. Kami meninjau semula penemuan saintifik utama daripada kerja ini dan menunjukkan bagaimana proses ini sedang mengubah bidang sains hutan tropika. Teras pendekatan kami memberi tumpuan terhadap penghubungan inisiatif akar umbi jangka panjang dengan protokol standar serta pengurusan data untuk mendapatkan hasil skala besar yang kukuh. Dengan menghubungkan penyelidik-penyelidik tropika dan meningkatkan status mereka, model Rangkaian Penyelidikan Sosial kami mengiktiraf kepentingan peranan pengasas data dalam penemuan saintifik. Bermula dengan pengasasan RAINFOR (Amerika Selatan) pada tahun 1999, rangkaian-rangkaian plot kekal kami kemudian disesuaikan untuk Afrika (AfriTRON) dan Asia Tenggara (T-FORCES) dan selanjutnya telah banyak dicontohi di seluruh dunia. Kini, inisiatif-inisiatif tersebut disepadukan melalui infrastruktur siber ForestPlots.net yang menghubungkan rakan sekerja dari 54 negara di 24 buah rangkaian plot. Secara kolektif, rangkaian ini sedang mengubah pemahaman tentang hutan tropika dan peranannya dalam biosfera. Kami telah bekerjasama untuk menemukan bagaimana, di mana dan mengapa karbon serta biodiversiti hutan bertindak balas terhadap perubahan iklim dan juga bagaimana mereka saling bermaklum balas. Kolaborasi pan-tropika jangka panjang ini telah mendedahkan sebuah sinki karbon jangka panjang serta arah alirannya dan juga menjelaskan pemandu-pemandu perubahan yang terpenting, di mana dan bagaimana proses hutan terjejas, masa susul yang ada dan kemungkinan tindakbalas hutan tropika pada perubahan iklim secara berterusan di masa depan. Dengan memanfaatkan pendekatan lama, rangkaian plot sedang menyalakan revolusi yang amat moden dalam sains hutan tropika. Pada masa akan datang, manusia sejagat akan banyak mendapat manfaat jika memupuk komuniti-komuniti akar umbi yang kini berkemampuan secara kolektif menghasilkan pemahaman unik dan jangka panjang mengenai hutan-hutan yang paling berharga di dunia. Instituto de Ecología Regional (IER) Universidad Nacional de Tucumán (UNT) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Facultad de Ciencias Agrarias Universidad Nacional de Jujuy James Cook University (JCU) CSIRO (Commonwealth Scientific and Industrial Research Organisation) School of Land & Food University of Tasmania CSIRO Tropical Forest Research Centre Independent Researcher Environmental Protection Agency (EPA) Centre for Tropical Environmental and Sustainability Science (TESS) College of Marine and Environmental Sciences James Cook University Centre for Tropical Environmental and Sustainability Science College of Science and Engineering James Cook University University of the Sunshine Coast University of York Flamingo Land Ltd. Sommersbergseestrasse Ghent University CAVElab Ghent University Royal Museum for Central Africa - Service of Wood Biology Isotope Bioscience Laboratory-ISOFYS Ghent University Gembloux Agro-Bio Tech Université de Liege Landscape Ecology and Vegetal Production Systems Unit CAVElab Computational & Applied Vegetation Ecology Ghent University Tropical Forestry Forest Resources Management Gembloux Agro-Bio Tech University of Liege Université Libre de Bruxelles (ULB) Evolutionary Biology and Ecology Royal Museum for Central Africa Royal Museum for Central Africa Ghent University Department of Environment Ghent University Service Evolution Biologique et Ecologie Belize Foundation for Research and Environmental Education IBIF Museo de Historia Natural Noel Kempff Mercado Universidad Autonoma Gabriel Rene Moreno PROMAB Museo Noel Kempff Consultor Independiente Jardin Botanico Municipal de Santa Cruz Museo de Historia Natural Noel Kempff Mercado Forest Management in Bolivia Universidad Autónoma del Beni Riberalta Museo de Historia Natural Noel Kempff Herbario del Sur de Bolivia Universidad Autónoma del Beni Conservation International Instituto de Biodiversidade e Floresta Universidade Federal do Oeste do Pará Universidade Federal de Pernambuco Universidade do Estado de Mato Grosso Universidade do Estado de Mato Grosso (UNEMAT) Projeto TEAM – Manaus Universidade Federal de Juiz de Fora (UFJF) Universidade Federal do Rio de Janeiro Instituto Nacional de Pesquisas da Amazônia Projeto Dinâmica Biológica de Fragmentos Florestais Departamento de Genética Ecologia e Evolução Universidade Federal de Minas Gerais Universidade Estadual de Campinas Laboratório de Ecologia de Comunidades e Funcionamento de Ecossistemas-ECoFERP Departamento de Biologia Faculdade de Filosofia Ciências e Letras USP National Institute for Space Research (INPE) Universidade Federal de Roraima (UFRR) UNESP - São Paulo State University Carbonozero Consultoria Ambiental Departamento de Biologia Universidade Federal do Amazonas (UFAM) Centro de Energia Nuclear na Agricultura Universidade de São Paulo UERR - Campus Rorainópolis Universidade Federal do Acre Instituto Agronômico de Campinas Universidade Federal do Rio Grande do Sul Embrapa Universidade Estadual do Norte Fluminense (UENF) Universidade Federal da Bahia (UFBA) Instituto de Biologia Universidade Estadual de Campinas Universidade Federal do Piauí (UFPI) Botany and Plant Ecology Laboratory Federal University of Acre INPA- Instituto Nacional de Pesquisas da Amazônia UERR - Campus Boa Vista Universidade Federal do Ceará Universidade Federal de Campina Grande Universidade Federal do Para Núcleo de Estudos e Pesquisas Ambientais Universidade Estadual de Campinas Instituto Federal de Educação Ciência e Tecnologia do Acre Instituto de Pesquisas Jardim Botânico do Rio de Janeiro Universidade Federal do Oeste do Pará UEFS Depto. de Ciências Biológicas Universidade Federal do Agreste de Pernambuco (UFAPE) Universidade Estadual de Montes Claros FFCLRP-USP/Br UNEMAT Universidade Federal de Jataí Universidade Federal do Pará Instituto de Ciências Biológicas Universidade de Campinas Universidade Federal de Lavras (UFLA) Museu Goeldi Embrapa Amazônia Oriental Instituto Nacional de Pesquisas da Amazônia UFMG - Universidade Federal de Minas Gerais Fundação Universidade Fedral de Rondônia - UNIR INPA- Instituto Nacional de Pesquisas Amazônicas Instituto Nacional de Pesquisas da Amazônia - Coordenação de Pesquisas em Silvicultura Tropical Jardim Botânico do Rio de Janeiro National Institute for Research in Amazonia Universidade Federal de Roraima (UFRR/PRONAT) Universidade Estadual de Campinas/UNICAMP Instituto Nacional de Pesquisas da Amazônia/CPBO Universidade Federal de Santa Catarina (UFSC) INCAPER- Instituto Capixaba de Pesquisa Assistência Técnica e Extensão Rural INPE- Instituto Nacional de Pesquisas Espaciais Universidade de São Paulo Instituto de Biociências Universidade Estadual Paulista Semiarid National Institute (INSA) Universidade de Brasília Departamento de Engenharia Florestal IBAM - Instituto Bem Ambiental Universidade do Estado de Mato Grosso Campus de Nova Xavantina University in Campinas Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) LMF Instituto Nacional de Pesquisas da Amazônia Universidade Federal do Vale do São Francisco USP - University of São Paulo Instituto Federal do Espírito Santo (IFES) INPA - Instituto Nacional de Pesquisas da Amazônia Grupo MAUA Universidade Federal de Mato Grosso Instituto de Ciências Naturais Humanas e Sociais Instituto Nacional da Mata Atlântica RAINFOR-PPBIO Universidade Federal Rural da Amazônia - UFRA/CAPES Universidade Federal do Amazonas (UFAM) INPA/Max-Planck Project EMBRAPA- Empresa Brasileira de Pesquisa Agropecuária (Amazônia Oriental) Serviço Florestal Brasileiro Museu Universitário Universidade Federal do Acre Universidade Federal Rural de Pernambuco PUCPR - Pontifícia Universidade Católica do Paraná Museu Paraense Emilio Goeldi Universiti Brunei Darussalam Environmental and Life Sciences Faculty of Science Universiti Brunei Darussalam Institute for Biodiversity and Environmental Research Universiti Brunei Darussalam Plant Systematic and Ecology Laboratory Department of Biology Higher Teachers’ Training College University of Yaounde I Faculty of Science Department of Botany and Plant Physiology University of Buea Faculty of Science Department of Plant Science University of Buea National Herbarium Plant Systematics and Ecology Laboratory Higher Teachers’ Training College University of Yaoundé I Department of Plant Biology Faculty of Sciences University of Yaounde 1 Bioversity International Faculty of Forestry University of Toronto Ministère des Eaux Forêts Chasse et Pêche (MEFCP) Universidad Católica de la Santísima Concepción Universidad de La Serena Research Institute of Tropical Forestry Chinese Academy of Forestry Kunming Institute of Botany Chinese Academy of Sciences Beijing Forestry University Universidad Nacional Abierta y a Distancia Red COL-TREE Corporación COL-TREE Nuevo Estándar Biotropical NEBIOT SAS Universidad del Tolima Asociación GAICA Universidad de Nariño – Red BST-Col Parques Nacionales Naturales Territorial Caribe – Red BST-Col Universidad del Atlantico – Red BST-Col Departamento de Ciencias Forestales Universidad Nacional de Colombia - Sede Medellín Socioecosistemas y Clima Sostenible Fundacion con Vida Parques Nacionales Naturales de Colombia – Red BST-Col Instituto de Investigación de Recursos Biológicos Alexander von Humboldt – Red BST-Col UNAL Instituto de Investigación Recursos Biologicos Alexander von Humboldt – Red BST-Col Fundación Jardín Botánico de Medellín Herbario “Joaquín Antonio Uribe” (JAUM) – Red BST-Col Universidad Nacional de Colombia sede Amazonia Coltree Facultad del Medio Ambiente y Recursos Naturales Universidad Distrital Francisco José de Caldas – Red BST-Col Universidad de Tolima Fundación Orinoquia Biodiversa – Red BST-Col Departamento de Biología Facultad de Ciencias Naturales Universidad Icesi – Red BST-Col Instituto de Ciencias Naturales Universidad Nacional de Colombia Universidad de los Llanos Servicios Ecoysistemicos y Cambio Climatico (SECC) Fundación Con Vida & Corporación COL-TREE Universidad del Rosario Fundacion Ecosistemas Secos de Colombia – Red BST-Col Universidad de los Andes - ANDES herbarium Institute of Botany Czech Academy of Sciences Palacky University Czech University of Life Sciences Mendel University World Wide Fund for Nature Wildlife Conservation Society-DR Congo Lukuru Wildlife Research Foundation Université de Kisangani Faculté des Sciences Laboratoire d'écologie et aménagement forestier Université de Kisangani Université de Kisangani Faculté des Sciences Agronomiques République Démocratique du Congo Ministère de l'Environnement et Développement Durable Aarhus University University of Copenhagen Escuela Politécnica Nacional del Ecuador Herbario Alfredo Paredes (QAP) Universidad Central del Ecuador Universidad Técnica Particular de Loja Grupo de Investigación en Biodiversidad Medio Ambiente y Salud-BIOMAS Universidad de las Américas, Campus Queri Keller Science Action Center The Field Museum, 1400 South Lake Shore Dr. Universidad Estatal Amazónica Facultad de Ingeniería Ambiental Universidad Tecnica del Norte Herbario Nacional del Ecuador Grupo de Ecosistemas Tropicales y Cambio Global Universidad Regional Amazónica ikiam Colegio de Ciencias Biológicas y Ambientales COCIBA & Extensión Galápagos Universidad San Francisco de Quito-USFQ Herbario de Botánica Económica del Ecuador QUSF Universidad San Francisco de Quito USFQ Galapagos Science Center USFQ UNC Chapel Hill University of North Carolina-UNC Chapel Hill University of Florida FindingSpecies Mekelle University Environment Climate Change and Coffee Forest Forum (ECCCFF) University of Turku Centre de coopération International en Recherche Agronomique pour le Développement (CIRAD) CNRS ONF INRAE Centre National de la Recherche Scientifique AMAP Univ Montpellier IRD CNRS CIRAD INRA Forêts et Sociétés (F&S) Centre de coopération International en Recherche Agronomique pour le Développement (CIRAD) Departement Hommes Natures Societes Museum national d'histoire naturelle INRA Cirad UMR Ecologie des Forêts de Guyane (AgroparisTech CNRS INRAE Université des Antilles Université de la Guyane) Ministry of Forests Seas Environment and Climate Rougier-Gabon Agence Nationale des Parcs Nationaux Gabon Commission of Central African Forests (COMIFAC) Agence Nationale des Parcs Nationaux Ministère des Forêts des Eaux de la Mer de l'Environnement Chargé du Plan Climat des Objectifs de Développement Durable et du Plan d'Affectation des Terres Institut de Recherche en Ecologie Tropicale (CENAREST) Gabon/Agence Nationale des Parcs Nationaux Georg-August-University Göttingen University of Freiburg Institute of Botany University of Hohenheim Max Planck Institute for Chemistry Forestry Research Institute of Ghana (FORIG) Mensuration Unit Forestry Commission of Ghana Center for International Forestry Research Iwokrama International Centre for Rainforest Conservation and Development Guyana Forestry Commission Utrecht University Centre for Sustainable Technologies Indian Institute of Science Centre for International Forestry Research (CIFOR) Herbarium Borgoriense Indonesian Institute of Sciences (LIPI) Indonesian Institute of Science Forest Research and Development Agency (FORDA) Balitek-KSDA Samboja University of Florence and MUSE - Museo delle Scienze Cirad Hokkaido University Graduate School of Agriculture Kyoto University Forestry Development Authority of the Government of Liberia (FDA) University of Liberia Sungai Wain Protection Forest South East Asia Rainforest Research Partnership Danum Valley Field Centre Malaysian Palm Oil Board Sabah Forestry Department Forest Research Centre Universiti Malaysia Sabah Sabah Forestry Department Sarawak Forestry Corporation Eduardo Mondlane University Herbarium UNAN-Leon Universidad Nacional Autónoma de Nicaragua University of Abeokuta Natural History Museum of Norway University of Oslo Norwegian University of Life Sciences Universidad Nacional de la Amazonía Peruana (UNAP) Universidad Nacional de Jaén Jardin Botanico de Missouri Andes to Amazon Biodiversity Program Universidad Nacional de San Agustín de Arequipa Facultad de Ciencias Biológicas Universidad Nacional de la Amazonía Peruana Kené - Instituto de Estudios Forestales y Ambientales Instituto de Investigaciones de la Amazonia Peruana (IIAP) Universidad Nacional Jorge Basadre de Grohmann (UNJBG) Universidad Nacional de San Antonio Abad del Cusco Centro de Conservación Investigación y Manejo CIMA Pontificia Universidad Católica del Perú Asociacion Bosques Perú Université Officielle de Bukavu Université Marien N'Gouabi Wildlife Conservation Society Ecole Nationale Supérieure d'Agronomie et de Foresterie Université Marien Ngouabi Univeriste Marien Ngouabi The Gola Rainforest National Park Department of Geography National University of Singapore Departamento de Biología y Geología Física y Química inorgánica Universidad Rey Juan Carlos Real Jardín Botánico – CSIC Departamento de Biología Área de Botánica Universidad Autónoma de Madrid Museo Nacional de Ciencias Naturales (MNCN-CSIC) Centre for Agricultural Research in Suriname (CELOS) Stockholm Environment Institute Department of Plant Ecology and Evolution Uppsala University Southern Swedish Forest Research Centre InfoFlora Conservatoire et Jardin Botanique Geneve National Chung Hsing University Sokoine University of Agriculture Naturalis Biodiversity Center Wageningen University Forest Ecology and Forest Management Group Tropenbos International Institute for Biodiversity and Ecosystem Dynamics University of Amsterdam Bureau Waardenburg BV Van Hall Larenstein University of Applied Sciences Van der Hout Forestry Consulting Utrecht University, Domplein 29 Wageningen University Plant Ecology and Nature Conservation Group Data for Sustainability Department of Zoology Entomology & Fisheries Sciences Makerere University The Institute of Tropical Forest Conservation (ITFC) Mbarara University of Science and Technology (MUST) George Washington University Makerere University Department of Forestry Biodiversity and Tourism Makerere University University of Stirling University of Kent School of Geography University of Leeds UK Centre of Ecology & Hydrology Lancaster University University of Oxford The Landscapes and Livelihoods Group (TLLG) Overseas Development Institute Manchester Metropolitan University University of Aberdeen University of Exeter School of GeoSciences University of Edinburgh University of Cambridge Department of Environment and Geography University of York Department of Geography University College London Imperial College School of Geography Earth & Environmental Sciences Birmingham Institute of Forest Research University of Birmingham University of Plymouth Geography College of Life and Environmental Sciences University of Exeter Lancaster Environment Centre Lancaster University University of Edinburgh School of Biology University of Leeds Royal Botanic Garden Edinburgh CENAREST & ANPN & Stirling University University of Bristol School of Biological Sciences Department of Plant Sciences University of Cambridge Living with Lake Centre Laurentian University Royal Botanic Gardens Kew The Royal Society for the Protection of Birds centre for Conservation Science Environmental Change Institute School of Geography and the Environment University of Oxford UK Centre for Ecology & Hydrology School of Geography and the Environment University of Oxford The Royal Botanic Gardens Department of Geography and Environmental Science University of Dundee School of Biological Sciences University of Southampton University of East Anglia Stirling University School of Earth and Environment University of Leeds Department of Plant & Soil Science School of Biological Sciences University of Aberdeen, Cruickshank Building Institute for Transport Studies University of Leeds UK Research & Innovation University of Nottingham University of Bangor Center for Tropical Research Institute of the Environment and Sustainability University of California Center for Tropical Conservation Nicholas School of the Environment Duke University Ecology and Evolutionary Biology University of Michigan Saint Louis Zoo Department of Organismic and Evolutionary Biology Harvard University Center for Global Discovery and Conservation Science Arizona State University Wildlife Conservation Society – Programme Congo Woods Hole Research Center The University of Michigan Herbarium Nicholas School of the Environment National Park Service University of California ForestGEO Smithsonian Tropical Research Institute University of Texas at Austin Smithsonian Institute Washington University in Saint Louis Center for Conservation and Sustainable Development at the Missouri Botanical Garden Smithsonian Tropical Research Institute Smithsonian Institution Forest Global Earth Observatory (ForestGEO) Forest Global Earth Observatory (ForestGEO) Smithsonian Tropical Research Institute George Mason University Missouri Botanical Garden Broward County Parks and Recreation Nova Southeastern University Science and Education The Field Museum Department of Biology Boston University Wake Forest University Department of Geographical Sciences University of Maryland San Diego Zoo Institute for Conservation Research Biology Department Washington State University Yale School of Forestry & Environmental Studies Columbia University Department of Environmental Science Policy and Management University of California Berkeley School of Earth Sciences and Environmental Sustainability Northern Arizona University Department of Geography and the Environment University of Texas at Austin UNELLEZ-Guanare Programa de Ciencias del Agro y el Mar Herbario Universitario (PORT) Ci Progress GreenLife Universidad Nacional Experimental de Guayana Instituto Venezolano de Investigaciones Científicas (IVIC) Universidad de los Andes Viet Nature Conservation Centre CIRAD School of Life Sciences University of Lincoln UNESP - São Paulo State University Instituto de Biociências Universidade Estadual Paulista Gordon and Betty Moore Foundation: 1656 FAPESP: 2012/51509-8 FAPESP: 2012/51872-5 Fundação de Amparo à Pesquisa do Estado de Goiás: 2017/10267000329 European Research Council: 291585 Gordon and Betty Moore Foundation: 5349 European Research Council: 758873 Belgian Federal Science Policy Office: BR/132/A1/AFRIFORD Belgian Federal Science Policy Office: BR/143/A3/HERBAXYLAREDD Vlaamse Interuniversitaire Raad: CD2018TEA459A103 CNPq: CNPq/PPBio/457602/2012-0 National Science Foundation: DEB 1754647 Natural Environment Research Council: E/M0022021/1 Royal Society: ICA/R1/180100 Natural Environment Research Council: NE/D005590/1 European Research Council: NE/F005806/1 Natural Environment Research Council: 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Introduction. Cet article propose une synthèse des connaissances actuelles sur la classification, l’écologie et la biologie des céphalophes des forêts denses humides d’Afrique centrale (genres Cephalophus et Philantomba). Il fait aussi le point sur les pressions anthropiques subies par ces mammifères terrestres. Littérature. De nombreuses publications sur les céphalophes vivant dans les forêts denses humides d’Afrique centrale se focalisent sur la chasse, qu’elle soit de subsistance ou commerciale, y compris le braconnage. La classification taxonomique des céphalophes ayant été récemment révisée, de nouvelles espèces ont été décrites, alors que leur écologie n’est que très peu documentée. Cette synthèse met en exergue les déficits en termes de connaissances scientifiques et propose les thématiques prioritaires pour de futures recherches.Conclusions. Bien que de nombreux domaines restent à explorer pour certaines espèces (utilisation de l’habitat, domaine vital, etc.), il est suggéré d’étudier en priorité les techniques de différenciation des espèces de céphalophes lors des inventaires, leur rôle dans la dynamique forestière et l’impact de l’exploitation forestière sur leurs populations., State of knowledge on duikers (genera Cephalophus and Philantomba) of central Africa rainforests. A reviewIntroduction. This article provides a synthesis of current knowledge on classification, ecology and biology of duikers living in central African rainforests (genera Cephalophus and Philantomba). It also provides an update on the anthropogenic pressures on these terrestrial mammals. Literature. Many publications on central African duikers are focused on subsistence or commercial hunting, and poaching. As the taxonomic classification of duikers has recently been revised, new species have been described with very little information available on their ecology. This synthesis highlights the gaps in the scientific knowledge and proposes priority themes for future research.Conclusions. Although many aspects remain to be explored for some species (i.e., habitat use, home range), it is suggested to investigate in priority: the inventory methods, the role of duikers in forest dynamics, and the impact of logging on their populations.

Tropical Africa is home to an astonishing biodiversity occurring in a variety of ecosystems. Past climatic change and geological events have impacted the evolution and diversification of this biodiversity. During the last two decades, around 90 dated molecular phylogenies of different clades across animals and plants have been published leading to an increased understanding of the diversification and speciation processes generating tropical African biodiversity. In parallel, extended geological and palaeoclimatic records together with detailed numerical simulations have refined our understanding of past geological and climatic changes in Africa. To date, these important advances have not been reviewed within a common framework. Here, we critically review and synthesize African climate, tectonics and terrestrial biodiversity evolution throughout the Cenozoic to the mid-Pleistocene, drawing on recent advances in Earth and life sciences. We first review six major geo-climatic periods defining tropical African biodiversity diversification by synthesizing 89 dated molecular phylogeny studies. Two major geo-climatic factors impacting the diversification of the sub-Saharan biota are highlighted. First, Africa underwent numerous climatic fluctuations at ancient and more recent timescales, with tectonic, greenhouse gas, and orbital forcing stimulating diversification. Second, increased aridification since the Late Eocene led to important extinction events, but also provided unique diversification opportunities shaping the current tropical African biodiversity landscape. We then review diversification studies of tropical terrestrial animal and plant clades and discuss three major models of speciation: (i) geographic speciation via vicariance (allopatry); (ii) ecological speciation impacted by climate and geological changes, and (iii) genomic speciation via genome duplication. Geographic speciation has been the most widely documented to date and is a common speciation model across tropical Africa. We conclude with four important challenges faced by tropical African biodiversity research: (i) to increase knowledge by gathering basic and fundamental biodiversity information; (ii) to improve modelling of African geophysical evolution throughout the Cenozoic via better constraints and downscaling approaches; (iii) to increase the precision of phylogenetic reconstruction and molecular dating of tropical African clades by using next generation sequencing approaches together with better fossil calibrations; (iv) finally, as done here, to integrate data better from Earth and life sciences by focusing on the interdisciplinary study of the evolution of tropical African biodiversity in a wider geodiversity context., SCOPUS: ar.j, info:eu-repo/semantics/published

Dans un monde confronté aux changements climatiques et à des pandémies en lien avec la destruction des milieux naturels, les enjeux liés à la préservation de la biodiversité sont dorénavant bien connus et ont donné lieu à des accords internationaux majeurs, comme le protocole de Nagoya. Dans ce contexte mondial, les recherches menées au Sud sont primordiales. Les contributions rédigées ici par des chercheurs dʼAfrique, de lʼocéan Indien, dʼAsie du Sud-Est et dʼEurope traduisent la vigueur de la recherche sur la biodiversité dans les pays intertropicaux francophones. Documenter la diversité des écosystèmes végétaux locaux, mieux connaître les savoirs traditionnels et les utilisations populaires des plantes ou des champignons, valoriser le rôle des collections botaniques, mais aussi identifier des chaînes de valorisation économique responsables, gérer durablement les écosystèmes et leurs ressources, élaborer des outils stratégiques pour une gouvernance environnementale basée sur la science et, enfin, montrer la nécessité de lʼimplication citoyenne et de lʼensemble des acteurs concernés, tels sont les grands thèmes déclinés ici. Cet ouvrage collectif intéressera tous ceux qui travaillent sur la biodiversité des écosystèmes intertropicaux. Il souligne la nécessité dʼune science de lʼaction au service du développement durable.

7. Sabicea sanguinosa (N. Hallé) Razafim. et al. in Taxon 57: 20. 2008 (Fig. 2E–F, 12E–F, 13A–B). ≡ Pseudosabicea sanguinosa N. Hallé in Adansonia ser. 2, 11: 313. 1971. Holotypus: GABON. Ogooué-Maritime: Petit Bam Bam, 21.VIII.1966, N. Hallé & Le Thomas 573 (P [P00077596]!; isotype: K [K000414623]!, MO [acc. no. MO-05067088] image seen, P [P00077597, P00077598]!). Distribution, ecology and phenology. – This species is endemic to coastal Gabon between the Ogooué and Komo estuaries, and grows in forest edges on coastal sandy soils; for more precise information see under infraspecific taxa. Flowers have been collected in February, from May to July and in October-November; fruits in January-February, August and October. Conservation status. – The extent of occurrence (EOO) of S. sanguinosa is estimated to be 4009 km ², and its area of occupancy (AOO) to be 48 km ²; both values are within the limit for “Endangered” status under subcriteria B 1 and B 2. The species is endemic to coastal Gabon, and is known from 14 specimens, representing nine subpopulations, four of which occur in the Wonga-Wongué Presidential Reserve. In spite of its limited range, S. sanguinosa occurs in a sparsely populated region, and is a locally abundant plant of secondary forest habitats, which benefits from small-scale forest clearing (e.g. that induced by selective logging). As a result, there is no evidence of a particular threat, and the species is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – This species, although endemic to Gabon, was omitted from the national checklist of SOSEF et al. (2006) where two specimens (Sosef et al. 1613 and Sosef et al. 1745, both of the typical subspecies) were cited as Pseudosabicea proselyta. It indeed shows some resemblance to Sabicea proselyta and S. rubiginosa, but is quite easily separated from both by the hirsute indumentum of its vegetative parts, and its leaves that are conspicuously bullate in life; it also has generally larger bracts and calyx lobes, the latter acute at apex (Table 1). Two subspecies are here recognised in S. sanguinosa. They differ only by the colour of their bracts and calyx lobes (dark red in subsp. sanguinosa and pale green in subsp. viridis), a character which is obvious in the field but not so in dry material, and was found to be constant in all populations studied. The two subspecies have separate ranges as far as is known, but since the intervening zone is hardly explored botanically, it is not impossible that they may come in contact., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on page 138, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge.","SOSEF, M. S. M., J. J. WIERINGA, C. C. H. JONGKIND, G. ACHOUNDONG, Y. AZIZET ISSEMBE, D. BEDIGIAN, R. G. VAN DEN BERG, F. J. BRETELER, M. CHEEK, J. DEGREEF, R. B. FADEN, P. GOLDBLATT, L. J. G. VAN DER MAESEN, L. NGOK BANAK, R. NIANGADOUMA, T. NZABI, B. NZIENGUI, Z. S. ROGERS, T. STEVART, J. L. C. H. VAN VALKENBURG, G. WALTERS & J. J. F. E. DE WILDE (2006). Checklist des plantes vasculaires du Gabon. Checklist of Gabonese vascular plants. Scripta Bot. Belg. 35."]}

3d. Sabicea floribunda var. paucinervis Wernham, Monogr. Sabicea: 73. 1914 (Fig. 7B). Lectotypus (designated here): CAMEROON. Reg. South: Gross-Batanga, 3.XII.1890, imm.fr., Dinklage 743 (P [P 03793520]!; isolectotype: WAG [WAG 0034480]!). Syntypus: CAMEROON. Reg. South: Kribi, 24.X.1891, buds, Dinklage 1391 (P [P 03793519]!, WAG [WAG 0034479]!). Distribution, ecology and phenology. – This variety occurs in southern Cameroon from Kribi to Campo, in Equatorial Guinea (Rio Muni) and in Gabon, where it is found mostly in the northwest (Crystal Mts) with one record further south in the Chaillu massif (Fig. 8). Its range locally overlaps with that of var. floribunda in Gabon and Equatorial Guinea. It grows in secondary forest regrowth, often along roads, 0–540 m in elevation. Flowers have been recorded from March to May and October to December; fruits in August-September and from November to March. Conservation status. – The extent of occurrence (EOO) of S. floribunda var. paucinervis is calculated to be 21,218 km ², a little above the limit for “Vulnerable” status under subcriterion B 1. Its area of occupancy (AOO) is estimated to be 80 km ², which falls within the limit for “Endangered” status under subcriterion B 2, but is certainly an underestimation given the low collecting density in most of its range. The taxon occurs in Atlantic Central Africa (Cameroon, Gabon and Equatorial Guinea) and is known from 21 specimens. It is found in secondary forest habitats where it appears to be locally common, and given its ecology there is no evidence of a particular threat; consequently, it is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – This taxon differs from other varieties by its leaves with fewer secondary veins (8–13 pairs only) and the generally sparser indumentum of its vegetative parts – the stems being glabrous or nearly so, and the leaves glabrous except on veins. Its original description is based on two syntypes, Dinklage 743 and Dinklage 1391 (B), both of which were presumably destroyed in the Second World War but have extant duplicates in P and WAG. The P sheet of Dinklage 743, which is the most complete, is chosen here as lectotype. Additional material studied. – CAMEROON. Reg. South: Kribi-Campo, 35 km S de Kribi, 4. I.1983, imm. fr., van der Zon 1983 (WAG); 3 km S of Kribi, Grand Batanga road, 25.X.1968, fl., Bos 3134 (BR, K, P, WAG, YA); 5 km S of Kribi, Grand Batanga road, 26.II.1969, fr., Bos 4005 (BR, P, WAG, YA); near Eboundja I, km 20 road Kribi-Campo, 4. I.1983, imm.fr., de Kruif 1020 (WAG, YA); Ebundja 2, village along road from Kribi to Campo, 17.III.2007, buds, Dessein 1640 (BR, P); 45 km on the road from Kribi to Campo, 3.XII.1974, fl., J. J. F. E. de Wilde 7784 A (BR, WAG); 10 km ENE Ebodje, soit 40 km S Kribi, 7.XII.1979, fl., Letouzey 15322 (BR, P, YA); Campo Ma’an National Park, 12.II.2012, fr., Sonké 5915 (BR, MO, YA); Campo-Ma’an area, Massif des Mamelles, Along the path to Mamelles highlands, 23.IV.2001, buds, Tchouto Mbatchou et al. 3223 (WAG); Dipikar, road to centre of Island, 7.V.2001, fl., van Andel et al. 3421 (WAG); Campo Ma’an National Park, road Kribi-Ebodje Along small logger’s road, c. 2.7 km from Lolabé village, 4.VIII.2001, fr., van Andel et al. 3827 (WAG). EQUATORIAL GUINEA. Litoral: Bata-Monson-Dibolo, Estrada kms 54–55, 15.X.1991, fl., Carvalho 4887 (BR, WAG); Bata-Mari, Estrada kms 62–63, 15.XI.1991, imm.fr., Carvalho 4949 (WAG). Centro-Sur: 4 km N de Mitong, 12.XII.2003, buds, Sonké 3136 (BR, BRLU, K). GABON. Estuaire: 89 km along the road Libreville-Assok, Mts de Cristal, 14.VIII.1978, imm.fr., F. J. Breteler & J. J. F. E. de Wilde 7 (BR, LBV, WAG); Crystal Mountains, 3 km NE of Kinguélé, 11.IX.1994, fr., F. J. Breteler et al. 12808 (LBV, WAG); km 10 Tchimbélé-Kinguélé, 11.II.1986, fr., Breyne 5102 (BR, LBV); Crystal Mountains, 8 km on the road Tchimbélé to Kinguélé (= 74 km on SEEG road), 15.XI.2004, fl. & fr., Wieringa et al. 5440 (BR, K, LBV, WAG). Ngounié: Chantier Leroy, rte à 13 km de Masika vers Yeno sur rte Mouila-Yeno, 12.II.1988, imm.fr., A. M. Louis 2733 (LBV, WAG). WoleuNtem: Tchimbélé, 0.5 km S of dam, 19.III.1990, fr., Wieringa 720 (BR, LBV, WAG)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 130-132, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge."]}

6. Sabicea rubiginosa O. Lachenaud, Zemagho & Sonké, sp. nov. (Fig. 2C–D, 11, 12A–D). Holotypus: GABON. Moyen-Ogooué: Mabounié, 00°46'15"S 10°32'52"E, 31.X.2014, Lachenaud et al. 2105 (BRLU!; isotype: BR [BR0000024387101]!, G!, LBV!, MO!, P!, WAG!). Habitu sarmentoso, ovario biloculare, inflorescentiis cymosis, foliis utrinque viridibus supra inter nervis glabrescentibus, corolla fauce pilis brevibus inflatis munita, fructibusque albogriseis cum granulis atris in mesocarpio S. proselyta similis, a quae differt calycis bracteisque atro-rubris (nec viridibus), seminibus striolatis (nec grosse reticulatis), calyce tubo intus glabro (nec villoso) et lobis extus villosis (nec puberulis), foliisque subtus cum indumento suberecto pilis brevibus albidis et pilis longioribus rufescentibus intermixtis (nec indumento omnino albido et appresso, raro inter nervis suberecto). Sarmentose liana, 1 –2 m high, climbing or occasionally creeping on the ground; stems cylindrical, 2 –5 mm thick, densely covered with c. 1 mm long rufous appressed hairs, intermingled with shorter uncinate hairs. Stipules interpetiolar, dark reddish-brown, 10 –15 × 6 –11 mm, erect, ovate and ± longitudinally plicate, rounded at base, acute at apex, uniformly pubescent outside with same indumentum as the stems, glabrous inside. Leaves opposite, equal; petiole 0.8–4.8 cm long, with same indumentum as the stems; lamina 6.5–17 × 2.3–7.7 cm, elliptic, acute at base, gradually acuminate at apex, slightly coriaceous, discolorous; upper side dark green, glabrous except for the midrib (and sometimes the secondary veins) with same indumentum as the stems; lower side pale green with brown-red veins, densely pubescent with both soft rufous hairs, 1–1.5 mm long appressed to half-erect, denser on the veins, and shorter whitish erect hairs 0.2 – 0.5 mm long; secondary veins 9–15 pairs, rather strongly ascending, eucamptodromous; tertiary veins markedly raised on lower leaf surface, much stronger than quaternary veins, the latter densely reticulate, forming areolae Inflorescences axillary and paired at nodes, cymose or sometimes glomeruliform at anthesis, many-flowered, 1.2–6.5 cm long, densely covered with rufous hairs c. 1 mm long intermingled with shorter uncinate hairs; peduncle 0.3–3.5 cm long; primary ramifications (0–) 0.2–2.3 cm long. Bracts dark red, free, appressed-pubescent outside and towards the apex inside, all recaulescent except the basal pair; basal bracts elliptic, entire or rarely dentate towards the base, 4–11 × 1.3–3.5 mm, acute at apex; median bracts elliptic, 4.5–8 × 1–1.7 mm; upper bracts narrowly elliptic, 1–4.5 × 0.2–0.8 mm. Flowers 5-merous, heterostylous; pedicels c. 0.5 mm long, densely villose. Calyx dark red, the base sometimes green or whitish; tube 0.6–0.7 mm long, villose outside like the inflorescence, glabrous inside; lobes narrowly spathulate, 1.5– 3 × 0.5 – 1.2 mm, obtuse to subacute and curved outwards at apex, villose outside, puberulous inside except towards the base, alternating with minute colleters. Corolla pale green in bud, whitish at anthesis; tube cylindrical, 4 –4.5 × 1.5 mm, outside glabrous at base and sparsely appressed-pubescent at apex, inside with a ring of multicellular hairs around the upper third and short, inflated unicellular hairs at the throat, the intervening zone with very sparse hairs; lobes triangular, 1.5 –1.8 × 1.3–1.5 mm, patent, shortly appressed-hairy outside, glabrous inside; flower buds obtuse, the apex slightly enlarged and pentagonal. Stamens included and attached around the upper third of the corolla tube (long-styled flowers) or half-exserted and attached near the apex of the tube (short-styled flowers); anthers sessile, elliptic, c. 1 × 0.6 mm, glabrous. Ovary c. 1.5 mm long, densely villose, 2-locular. Disk cylindrical, c. 0.5 mm long, glabrous, slightly shorter than the calyx tube. Style c. 4.3 mm long and just reaching throat (long-styled flowers) or c. 3.5 mm long and included (short-styled flowers), bifid, with elliptic flattened stigmas c. 0.8 mm long, these shortly stipitate in long-styled flowers and sessile in short-styled flowers. Fruits whitish, ellipsoid, with persistent calyx, 5–10 × 4–8 mm in life, 4–10 × 3–9.5 mm when dry, villose, with pedicel 0.5–3.5 mm long; mesocarp very soft, whitish, c. 1.5 mm thick, with numerous darker granules. Seeds numerous, pale brown, polyedric, c. 0.8 × 0.5 mm, the surface finely striolate. Etymology. – The epithet rubiginosa refers to the rustycoloured indumentum of the leaves and stems. Distribution, ecology and phenology. – Sabicea rubiginosa is endemic to west-central Gabon, south to Rabi and north to the lower Ngounié river (Fig. 10) and is locally very abundant in its range. It occurs in forest edges, especially along tracks, at low elevations (20–165 m). Flowers have been recorded in January, March, May, July and October-November, probably most of the year; fruits from January to March, in June-July and in October-November. Conservation status. – The extent of occurrence (EOO) of S. rubiginosa is estimated to be 4312 km ², and its area of occupancy (AOO) to be 88 km ², both values being within the limit for “Endangered” status under subcriteria B 1 and B 2. The species is endemic to west-central Gabon and is known from 30 specimens, representing five subpopulations, none of which is protected. One of these is situated in a forestry concession, which does not seem to represent a serious threat since the species occurs in forest edges and is likely to be favoured by selective logging. Two subpopulations occur in oil concessions, and one in a mining concession where an important exploitation project is scheduled; a decline in habitat extent and quality and number of individuals is therefore predicted. The five subpopulations represent five locations in the sense of IUCN (2012), and the species qualifies for “Endangered” [EN B 1ab(iii,v)+2ab(iii,v)] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – Sabicea rubiginosa has previously been mistaken for S. proselyta (see that species), but differs by the indumentum of its lower leaf surface, the ornamentation of its seeds, the absence of hairs inside the calyx tube, and the dark red colour of its bracts and calyces (Table 1; Fig. 12A, C). The latter character is especially conspicuous in the field, and makes S. rubiginosa a remarkably attractive plant, which could certainly be grown for ornamental purposes. The typical subspecies of S. sanguinosa also has red bracts and calyces, but differs by the hirsute and whitish (not rufous) indumentum of its vegetative parts, its leaves that are markedly bullate in the fresh state, its calyx lobes acute at apex and its generally larger bracts (Table 1). The three species, S. proselyta, S. rubiginosa and S. sanguinosa, appear to have separate ranges (Fig. 10). Paratypi. – GABON. Moyen-Ogooué: Mabounié, forest area south-west of camp, 6.V.2012, fl., Bidault 470 (BRLU, P); zone de Mabounié, à 45 km au SW de Lambaréné, rive N de la rivière Ngounié, 16.XI.2013, fl., Bidault et al. 1329 (BRLU); Concession froestière GWT, 5.VI.2012, fr., Boupoya & al. 727 (BRLU); Ezanga, 1.II.1991, fr., Dibata 727 (WAG); Mabounié, 13.X.2012, fl., Sonké & Ikabanga 5999 (BR, BRLU, LBV, MO); ibid. loco, 13.X.2012, fr., Sonké & Ikabanga 6001 (BR, LBV, MO); ibid. loco, 23.X.2012, fl., Sonké & Ikabanga 6132 (BR, BRLU, LBV, MO); ibid. loco, 24.X.2012, fl., Sonké & Ikabanga 6140 (BR, BRLU, LBV, MO); ibid. loco, 24.X.2012, fl., Sonké & Ikabanga 6141 (BR, BRLU, LBV, MO); ibid. loco, 25.X.2012, fl. & fr., Sonké & Ikabanga 6153 (BR, BRLU, LBV, MO); ibid. loco, 25.X.2012, fl., Sonké & Ikabanga 6155 (BR, BRLU, LBV, MO); Mabounié, 1.V.2012, buds, Stévart et al. 4125 (BRLU, LBV); ibid. loco, Ngounié River, 4.V.2012, fl., Stévart & Issembé 4176 (BRLU, LBV); Mabounié mine, near Lambaréné, 9.II.2012, imm.fr., Stévart & Droissart 4206 (BRLU, LBV, P). Ngounié: forêt sur la rive gauche (S) de l’Ikoy, à env. 10 km de l’embouchure avec la Ngounié, 26.X.2012, fl., Dauby et al. 2938 (BRLU, LBV); concession Maurel & Prom, près du Lac Ezanga, 22.XI.2013, fl., Lachenaud et al. 1531 (BR, BRLU, LBV, MO, P, WAG); Mabounié, le long de la rivière Ngounié, 12.X.2012, buds, Sonké & Ikabanga 5972 (BR, BRLU, LBV, MO). Ogooué-Maritime: Rabi, 28.III.1990, fl. & fr., F.J. Breteler et al. 9576 (BR, G, LBV, P, WAG); Rabi-Kounga, 8.VII.1998, fl. & imm.fr., F.J. Breteler et al. 14350 (BR, LBV, WAG); Rabi-Kounga, S of Rabi, 1.I.1994, fl. & fr., Haegens & van der Burgt 222 (BR, LBV, WAG); c. 15 km NW of Shell oil exploitation Rabi, 23.XI.1989, fl. & fr., J.J.F.E. de Wilde et al. 9688 (LBV, WAG); Rabi (parcelle Smithsonian), 9.XI.2014, fl., D. Nguema et al. 2843 (BRLU); Pechoud road southwards, 27.X.1990, fr., van Nek 128 (BR, LBV, WAG); Rabi-E, near Pechaud camp, 4.XI.1990, fl. & fr., van Nek 190 (BR, LBV, WAG); Rabi-Kounga, in between Shell-office and camp, 27.X.1992, fl. & fr., von Asmuth & Vosmeer 35 (WAG); Rabi-Kounga, road to Echira, 5.XI.1992, buds, von Asmuth & Vosmeer 58 (WAG); Rabi-Kounga, road to Echira, 5.XI.1992, fl., von Asmuth & Vosmeer 59 (WAG); Rabi, 4½ km on road to Divangui, 4.III.1994, fr., Wieringa & Haegens 2389 (LBV, WAG).

8. Sabicea segregata Hiern in Oliv., Fl. Trop. Afr. 3: 77. 1877 (Fig. 2G–H, 13C–F). ≡ Pseudosabicea segregata (Hiern) N. Hallé in Adansonia ser. 2, 3: 172. 1963. Lectotypus (designated here): GABON or EQUATORIAL GUINEA: River Muni, VIII. 1862, Mann 1766 (K [K000414626]!; isolectotype: P [P00077599]!). = Sabicea henningsiana Büttner in Bot. Vereins Prov. Brandenburg 31: 79. 1889. Lectotypus (designated here): GABON. Estuaire: Sibangefarm, IX.1884, fl., Büttner 437 (K!). Syntypus: GABON. Estuaire: Sibangefarm, X.1884, Büttner 443 (B †). Distribution, ecology and phenology. – This species occurs in southern Cameroon where rare, Equatorial Guinea (Rio Muni), Gabon where very common and widespread (though absent in southeast, extreme northeast, and lower Ogooué basin), and southwestern Republic of Congo (Fig. 14). It is found in secondary forest, edges and regrowth, and in fringing forest on inselbergs, always on drained soils, on various substrates (sandy or clayish), 0–1080 m in altitude. Flowers and fruits have been recorded in all months. Conservation status. – The extent of occurrence (EOO) of S. segregata is estimated to be 250,602 km ², and its area of occupancy (AOO) to be 396 km ². The latter value falls within the limit for “Vulnerable” status under criterion B 2, but is an obvious underestimation given the low collecting density in most of its range and the fact that the species is generally common there. The species occurs from south Cameroon to the Republic of Congo, and is known from 124 specimens representing 71 subpopulations. It occurs in several protected areas: Campo Ma’an National Park in Cameroon, Monte Alén National Park in Equatorial Guinea, Lopé, Waka, Doudou Mountains and Ivindo National Parks in Gabon, and Dimonika Biosphere Reserve in the Republic of Congo. In view of its wide distribution, abundance, and preference for degraded forest habitats, it is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – This species is closely related to S. floribunda, both having the corolla lobes brown at anthesis, unlike other species of the group. The differences between them are summarised in the key. The calyx lobes of S. segregata are usually longer and narrower than in other species of the group, but there is limited overlap with S. floribunda in this character. Most collections of S. segregata, including the type, have stems with appressed hairs, but a variant with hirsute stems occurs in Gabon, particularly in the east of the country. The fruits apparently turn from whitish to red to purple-black; however, since the last colour is much less commonly reported than the other two, it is not sure whether this sequence is always followed. The original description of S. segregata (HIERN, 1877) does not mention the type number, but the only possible candidates are Mann 1766 in Kew, and Mann s.n. in Paris, the latter being almost certainly an unnumbered duplicate of the former. The Kew sheet is here selected as lectotype. It is not known on which side of the Muni River, which forms the border between Equatorial Guinea and Gabon, this material was collected. The description of S. henningsiana (BÜTTNER, 1889) is based on two syntypes, Büttner 437 and Büttner 443, both from Sibang in Gabon. The original sheets of both specimens have presumably been destroyed in Berlin, but a duplicate of the former remains in Kew, and is here selected as lectotype. Additional material studied. – CAMEROON. Reg. South: Campo-Ma’an area, Ebodje, Along the beach, 20.II.2000, fr., Elad et al. 1367 (WAG); Campo-Ma’an area, Mvini, Bigan, Along Trasect 7, 16.II.2000, imm.fr., Tchouto Mbatchou et al. 2524 (WAG); Bipindi, s.d., buds, Zenker s.n. (BR, P). EQUATORIAL GUINEA. Centro-Sur: Parc National de Monte Alen, dalle rocheuse d’Engong, 5 km à l’W du village d’Engong, 12.V.2002, fr., Parmentier & Esono 2781 (BRLU); 4 km N de Mitong, 12.XII.2003, imm.fr., Sonké 3138 (BR, BRLU, K); 6 km N de Mitong, 12.XII.2003, fl., Sonké 3151 (BR, BRLU, K); Engong, 14.VIII.2001, fl., Sonké & Esono 2546 (BR, BRLU, WAG); Engong, 14.VIII.2001, fr., Sonké & Esono 2552 (BR, BRLU, WAG). Litoral: Bata-Monson-Dibolo: Estrada kms 54– 55, 15.X.1991, fl., Carvalho 4889 (BR, BRLU, WAG); Bata-Nasanga: Estrada km 14, 17.X.1991, fl., Carvalho 4890 (WAG); Bata-Mari: Estrada kms 62– 63, 15.XI.1991, imm.fr., Carvalho 4952 (WAG); Engong, 28.VII.1999, fr., Eneme 439 (BRLU); Etembue, 15.IX.2001, buds, Esono & Ndong 335 (BRLU); Ndote Nord, 28.VIII.1997, fr., Lisowski M-153 (BRLU). Reg. unknown: Akanabot, 15.IX.2001, fr., Esono & Ndong 351 (BRLU). GABON. Estuaire: Mondah Forest on Cape Esterias, c. 22 km on the road from Libreville, 3.IX.1978, fl. & fr., F.J. Breteler et al. 408 (BR, K, WAG); plantations de Assoukou, près du poste de Kango, 2.X.1912, buds, Chevalier 26847 (K, P); plantation Stéphane, sur la Bokoué, 9.X.1912, fl., Chevalier 26989 (P); vieux chantier ‘Sango’, Ntoum, 9.X.1987, fl., Dibata 320 (BR, WAG); Nkoulounga, 31.I.1961, fl., N. Hallé 1024 (P); sine loco, 15.X.1896, fl., Klaine 100 (P); sine loco, 12.IX.1896, fl., Klaine 123 (P); Env. de Libreville, 18.VIII.1898, fl. & fr., Klaine 377 (P); env. de Libreville, 1897, fr., Klaine 771 (P); Env. de Libreville, 15.VI.1897, fr., Klaine 962 (P); env. de Libreville, 5.X.1901, fl. & fr., Klaine 2432 (BR, K, P); km 31 Kougouleu-Atogafina, NE of Kouamé, 19.XI.1982, imm.fr., Leeuwenberg 12554 (LBV, WAG); rte Cap Santa-Clara, 6 km à droite, 31.I.1985, fr., A.M. Louis & J.M. Reitsma 1677 (BR, LBV, WAG); Forêt Classée de la Mondah, 0°32'48"N 9°19'40"E, 20.II.1994, fr., Lowry 4566 (LBV); c. 15 km N. of Libreville, 18.III.1987, fr., J.M. & B. Reitsma 3166 (LBV, WAG); forêt de la Mondah. 5 km on off road to Santa Clara from Cap Esterias road, 11.XI.1988, fl., van der Maesen et al. 5440 (WAG). Haut-Ogooué: concession CEB, W of Okandja, 19.XI.2015, imm. fr., Texier & Akouangou 174 (BRLU). Moyen-Ogooué: Mabounié, à 45 km au SW de Lambaréné, rives de la Ngounié, 15.X.2012, fl., Bidault et al. 845 (BRLU, LBV, P); ibid. loco, 16.X.2012, buds, Bidault et al. 906 (BRLU, LBV); ibid. loco, 15.XI.2013, fl., Bidault et al. 1316 (MO); au S de Lambaréné, entre 5 et 10 km depuis la ville, entre l’Ogooué et la rte de Fougamou, 13.IV.2015, fr., Bidault et al. 1922 (BR, BRLU); Concession forestière GWT (Global Wood and Trading), 5.VI.2012, imm.fr., Boupoya & al. 744 (BRLU); Mboumi, 16.I.2000, fr., Champluvier 6008 (BR); ibid. loco, 16.I.2000, fr., Champluvier 6019B (BR); c. 10 km NNW of Ndjolé, on BSO forestry road, 26.II.2008, fl., Dessein et al. 2148 (BR, LBV, MO, WAG); Ayem, 10 km SW de Ndjolé, 11.IV.1963, fl., N. Hallé 1621 (P); Ayem, 10 km SW de Ndjolé, 30.IV.1963, fl. & fr., N. Hallé 1952 (P); Ayem, 10 km SW de Ndjolé, 6.V.1963, fl., N. Hallé 2007 (P); N of lake Azingo, 4.VI.2014, imm.fr., Libalah & Ikabanga 3 (BR, BRLU); Mabounié, 18.X.2012, fl., Sonké et al. 6108 (BR, BRLU); ibid. loco, 23.X.2012, fl., Sonké & Ikabanga 6127 (BR, BRLU); ibid. loco, 23.X.2012, fl., Sonké & Ikabanga 6137 (BR, BRLU); ibid. loco, 23.X.2012, fl. & fr., Sonké & Ikabanga 6139 (BR, BRLU, P); Rougier Logging Concession, Haut Abanga. East of Ndjolé, 17.II.2012, fr., Stévart et al. 4301 (BRLU, LBV, P); Ndjolé, I.1895, fr., Thollon 117 (P); roadside between Ndjole town and railway station, 22.VII.1986, fr., Thomas & Wilks 6589 (LBV, P, WAG). Ngounié: Waka forest exploitation road, 19.XI.1984, fl., Arends et al. 301 (BR, K, LBV, P, WAG); PN de Waka, 1°10'34"S 11°08'02"E, 28.XI.2007, imm.fr., Boussengui-Nongo et al. 313 (LBV); Mouyanama falls, at base of Mt Songou, 22.II.2008, fr., Dessein et al. 2041 (BR, LBV); entre Pagha & Mouteti, 26.XI.1924, fl., Le Testu 5104 (BM, BR, K, P, WAG); Parc national de Waka, près du Camp Oghoubi, 24.VI.2006, fr., J. Mayombo et al. 1559 (LBV); 25 km on the road Ikobey to Egoubi camp, 1.IV.2004, fr., Wieringa et al. 5204 (LBV, WAG); road Mouila to Yeno, c. 2 km before Issinga, 8.III.2013, fr., Wieringa et al. 7169 (WAG). Nyanga: rte Tchibanga-Ndende, 25.X.2009, fl., Bissiengou et al. 540 (BR, LBV, WAG); 48 km SSW of Doussala, road Doussala-Igotshi, 21.III.1988, fr., J.J.F.E. de Wilde et al. 9485 (BR, K, LBV, WAG); Tchibanga, IX.1915, fl., Le Testu 2120 (BM, BR, K, P); concession SFN, 30.X.2003, fl. & imm.fr., van Valkenburg et al. 2523 (BR, K, LBV, P, WAG); forestry concession of Bakker, 6 km N of Igotchi, 29.X.2003, fl., Wieringa et al. 5025 (BR, K, LBV, WAG); forestry concession of Bakker, 15 km NNE of Igotchi, 31.X.2003, fl., Wieringa et al. 5047 (LBV, WAG). Ogooué-Ivindo: concession forestière Rougier-Ivindo. En bordure du fleuve, au N de la concession, 29.X.2015, fl., Bidault et al. 2269 (BR); Mintoume, 5.II.2005, fr., Boupoya & Mbazza 185 (BRLU); station de recherche de Mpassa, 10 km S de Makokou, 9.III.1984, fl., Doumenge 191 (LBV, P); M’passa, Ile aux chauve-souris, 17.III.1977, fr., Florence 55 (LBV, P); M’passa, 1.VI.1977, fl., Florence 496 (LBV, P); La Nké, ancienne zone d’exploitation, 8.X.1983, buds, Floret et al. 1732 (WAG); piste du Bouéni, 20 km SE Makokou, 11.II.1961, fr., N. Hallé 1131 (P); Makokou, Mission Catholique, 16.II.1961, imm.fr., N. Hallé 1185 (P); ± 50 km SE Makokou, 19.X.1964, buds, N. Hallé 2695 (P); 9 km SSW of Makokou, near Ivindo R., right bank, 2.XI.1977, fl., Leeuwenberg 11418 (BR, K, WAG); Mintome, 30.III.2003, fr., Mboma et al. 64 (LBV, WAG); Ivindo National Park, rte Langoué, 11.IV.2004, fr., Moungazi 1557 (BR, LBV, WAG); Ivindo National Park, Massouna 2000, 0°08.90'S 12°27.10'E, 6.XII.2003, imm.fr., D. Nguema Ekomo 507 (LBV) & 508 (LBV); bac de l’Ogooué, 19.VIII.1983, imm.fr., Sita 4964 (LBV); Kongou waterfall area, 00°17'25"N 012°34'22"E, 8.II.2018, imm.fr., Texier et al. 2282 (MO); Lopé, West Woods, 26.X.1990, buds, L. White 172 (LBV); Lope Reserve, 15.X.1995, buds, L. White 1495 (LBV, WAG). Ogooué-Lolo: Bambidie, c. 30 km E of Lastoursville, 2.V.1992, fl., F.J. Breteler et al. 11248 (LBV, WAG); Makande surroundings, c. 65 km SSW of Booué, 2.II.1999, imm.fr., F.J. Breteler et al. 14892 (WAG); Makandé, débardage Héron, 20.XI.1993, fl., Dhetchuvi et al. 1372 (BRLU); Vers 10 km rte Makandé-Gongué, 3.XII.1993, fl. & imm.fr., Dhetchuvi et al. 1597 (BR, BRLU, K, WAG); Lastoursville, concession forestière CEB, 30.XI.2012, fl., Ikabanga & Haurez 343 (BRLU); c. 50 km SE of Achouka, old forest in Région des Abeilles, 17.XI.1983, fl., A.M. Louis et al. 756 (BR, K, P, WAG); Camp Makande, 16.XII.1993, imm. fr., Moungazi 967 (LBV); Camp concession SEEF, area of Mount Ngouadi, 00°16'12"S 013°05'00"E, 10.III.2017, fr., Texier et al. 707 (LBV, MO); ibid. loco, 00°17'20"S 013°10'40"E, 11.III.2017, fl., Texier et al. 795 (LBV, MO); ibid. loco, 11.III.2017, fr., Texier et al. 798 (LBV, MO); SIAEFG logging concession, 30 km N of Pana, 01°28'44"S 12°32'55"E, 9.XII.2017, fl., Texier et al. 1564 (LBV, MO); S of Road Lopé-Lastoursville, c. 60 km, 00°43'21"S 012°28'30"E, 18.XII.2017, imm.fr., Texier et al.1761 (LBV, MO). Ogooué-Maritime: Toucan, 12.X.2002, fl., Bourobou et al. 993 (LBV, P, WAG); Rabi, c. 1°55'S 9°52'E, 13.X.2002, fr., Bourobou et al. 1022 (LBV); Gamba, 24.IX.1968, buds, Breteler & van Raalte 5675 (BR, WAG); Foot of Doudou Mountains, 25–35 km W of Mandji, 15.II.2008, fr., Dessein et al. 1862 (BR, LBV); between Rabi and Echira, 27.III.1990, fr., F.J. Breteler et al. 9557 (LBV, WAG); Rabi-Kounga, near Rabi 44, 1.I. 1994, fr., Haegens & van der Burgt 226 (LBV, WAG); Rabi-Kounga, 15.X.1991, fr., Schoenmaker 33 (WAG); Pechoud road southwards, 27.X.1990, fl., van Nek 124 (BR, LBV, WAG); Rabi, 4½ km on road to Divangui., 4.III.1994, fr., Wieringa & Haegens 2387 (BR, LBV, WAG). Woleu-Ntem: c. 6 km SSW of Mitzic, FOREENEX forest exploitation, 6.XI.2009, fl., Bissiengou et al. 703 (LBV, WAG); Parc des Monts de cristal, 13.II.2010, fl., Bissiengou & Niangadouma 975 (LBV, WAG); between Zomoko and Saint Germain, c. 10 km SE of Mitzic, 17.IV.1988, fr., F.J.Breteler & Dibata 8771 (BR, K, LBV, WAG); 5–10 km E of Saint Germain, E of Okano River, 20.IV.1988, fl., F.J. Breteler & Dibata 8866 (BR, K, LBV, WAG); Mts de Cristal, inselberg Milobo, 10km N Mbé Akélayong, 50km W Medouneu, 3.XII.2001, fl., Degreef 254 (BR); SEEG road near Tchimbélé, pylone 7, 6.II.2008, fr., Dessein et al. 1723 (BR, LBV); Angoum, VII.1933, buds, Le Testu 9199 (BM, P); Along forestry road Oveng-Mitsic, 28.III.1985, fl., J.M. Reitsma & B. Reitsma 731 (LBV, WAG); Tchimbélé Dam, Crystal Mountains, road N. of dam., 12.XI.2000, fl., Walters et al. 499 (BR, LBV, WAG). REPUBLIC OF CONGO. Kouilou: rte de Dimonika à Pounga, 24.XI.1978, fr., Cusset 520 (K, P, WAG); env. de Dimonika, M’Bulu Pambu, 7.III.1980, fr., Cusset 956 (P); env. de Dimonika, après Makaba carrefour, 13.XII.1982, fr., Cusset 1173 (P); Makaba, ancien village Manengue, 17.II.1987, fr., de Foresta 1296 (P); rte de Sounda (Pointe-Noire), 8.II.1966, imm.fr., Farron 5024 (P); near Koulila, 6.XII.1990, imm.fr., LaCroix 5005 (K); Kakamoeka, 11.X.1990, buds, Lisowski B-8005 (BR, K, WAG); en allant vers Makaba, village à 17 km de Dimonika, 4.XII.1972, fr., Makany 2045 (P); N’Tiétié, forêt à 3 km du village, 8.XII.1974, fl., Sita 3807 (BR, P). Niari: Mayombe au col de Bamba, 8.XII.1990, fl. & imm.fr., Dowsett-Lemaire 1392 (BR)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 140-142, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge.","HIERN, W. (1877). Rubiaceae. Fl. Trop. Afr. 3: 33 - 247.","BUTTNER, R. (1889). Neue Arten von Guinea, dem Kongo und dem Quango. Bot. Vereins Prov. Brandenburg 31: 64 - 96."]}

3. Sabicea floribunda K. Schum. in Bot. Jahrb. Syst. 23: 428. 1897 (Fig. 7A–B). ≡ Pseudosabicea floribunda (K. Schum.) N. Hallé in Adansonia ser. 2, 3: 172. 1963. Lectotypus (designated by HALLÉ, 1966: 216): CAMEROON. Reg. South: Lolodorf, 1896, Staudt 1 (P [P00077586]!; isolectotype: COI!, G [G00014620]!, S [S05-10061] image seen). Syntypus: CAMEROON. Reg. South: Lolodorf, 1896, imm.fr., Staudt 159 (G [G00014619]!, K [K000414629]!, P [P03793513]!). Distribution, ecology and phenology. – A common and widespread central African species, occurring from southern Cameroon to eastern D.R. Congo with an isolated population in eastern Nigeria. It grows in secondary forest, edges and regrowth, on both drained and flooded soils, 0–1250 m in altitude. For more precise information see under infraspecific taxa. Flowers and fruits throughout the year. Conservation status. – The extent of occurrence (EOO) of Sabicea floribunda is calculated to be 2,017,090 km ², well above the limit for “Vulnerable” status under subcriterion B1. Its area of occupancy (AOO) is estimated to be 344 km ², which falls within the limit for “Endangered” status under subcriterion B2, but is an obvious underestimation given the low collecting density in most of its range. The species occurs from Nigeria to the Democratic Republic of Congo, and is known from 108 specimens. It is a common species of secondary forest habitats, and not in any way threatened; consequently, it is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – The original description of S. floribunda (SCHUMANN, 1897) is based on two syntypes, Staudt 1 and 159. HALLÉ (1966: 216) cited the P sheet of Staudt 1 as “type”, which can be accepted as an implicit lectotypification. This species is the most widespread of the group, and the only one occurring east of the Congo River. It has usually been regarded as monotypic (e.g. HALLÉ, 1966) but a careful examination of the material shows that it can be quite easily separated into four distinct taxa, which differ mostly in characters of the bracts and the vegetative parts (Table 2) – the flowers and fruits being apparently identical. These taxa have mostly separate distributions but locally come in contact (Fig. 8) and are here recognised as varieties. When they are better studied in the field, especially in their areas of sympatry, some of them (in particular var. anisostegia) may eventually be raised to specific rank. The illustration of S. floribunda published in HALLÉ (1966: 217) represents var. anisostegia. Sabicea floribunda is very closely related to S. segregata. The two species share, in particular, lax inflorescences and corolla lobes brown at anthesis, and are not safely separable by vegetative characters. Since they frequently grow side by side, mixed collections are occasionally made (e.g. Champluvier 6019 was initially a mixture of both species). Fertile specimens can be identified with the characters mentioned in the key. The length of calyx lobes was used by HALLÉ (1966: 200) as the main diagnostic character, but in fact shows some (limited) overlap between the two species., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 124-126, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["HALLE, N. (1966). Rubiacees (1 e partie). Fl. Gabon 12.","IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge."]}

4. Sabicea nobilis R.D. Good in J. Bot. 61: 86. 1923 (Fig. 1G–H, 7C–D). ≡ Pseudosabicea nobilis (R.D. Good) N. Hallé, Fl. Gabon 17: 2. 1970. Lectotypus (designated here): ANGOLA. Cabinda: Belize, 16.XI.1918, fl., Gossweiler 7550 (BM [BM000902997]!; isolectotype: K [K000414624]!, LISC [LISC000807, LISC000808] images seen). Syntypus: ANGOLA. Cabinda: Belize, 12.III.1917, fr., Gossweiler 7043 (BM!, LISC [LISC000809, LISC000810, LISC000811] images seen). = Pseudosabicea mitisphaera N. Hallé in Adansonia ser. 2, 3: 170. 1963. Holotypus: GABON. OgoouéIvindo: piste du Bouéni, env. 20 km SE Makokou, 11.II.1961, N. Hallé 1129 (P [P00077593]!; isotype: BR [BR0000008852137]!, K [K000414625]!, LISC [LISC002621] image seen, P [P00077594]!). Distribution, ecology and phenology. – Sabicea nobilis occurs in southeastern Cameroon, Gabon (mostly in the east, absent from the coastal area), southwestern Congo Republic, and Angola (Cabinda) (Fig. 9) and is locally common in its range. It is found in secondary forest, edges and regrowth, always on drained soils, 160–800 m in elevation. Flowers have been collected from May to August and October to January; fruits from January to May and September to November. Conservation status. – The extent of occurrence (EOO) of S. nobilis is calculated to be 238,406 km ², well above the limit for “Vulnerable” status under subcriterion B 1. Its area of occupancy (AOO) is estimated to be 132 km ², within the limit for “Endangered” status under criterion B 2, but this is an obvious underestimation since most of its range is not well explored. It occurs in Atlantic Central Africa from southeastern Cameroon to Cabinda (Angola) and is known from 43 specimens representing 30 subpopulations. It occurs in two protected areas, the Doudou Mountains National Park and Batéké Plateaux National Park in Gabon. It is a locally abundant plant of forest edge habitats, and is thus favoured by small-scale forest clearing. Furthermore, most of the area where it occurs is sparsely populated. As a result, there is no particular threat to the species, which is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – The original description of S. nobilis (GOOD, 1923) is based on two syntypes, Gossweiler 7043 and 7550, both at BM; the latter collection is here selected as lectotype, because it has a larger number of duplicates. Additional material studied. – CAMEROON. Reg. East: South of Echiambor (Lomié to Ngoila), 18.II.1978, fr., Lowe 3515 (K); Nkamouna, 11.VI.2004, buds, Sonké 3480 (BR, BRLU, K); ibid. loco., 15.VI.2004, fl., Sonké 3525 (BR, BRLU, K). Reg. South: E Sangmelima, 16.V.2016, fr., Sonké & Zemagho 6338 (BR, BRLU, K, MO, WAG, YA). GABON. Haut-Ogooué: c. 5–10 km of Franceville along road to Okondja, 4.III.1999, fr., Andersson & Nilsson 2316 (BR); Lekoko forest exploitation, 70 km SSW of Moanda, near the border Congo-Gabon, 13.X.1970, fr., F.J. Breteler 6871 (BR, WAG). Moyen-Ogooué: CEFA Ayem, 10 km SW Ndjolé, 10.V.1963, fl., N. Hallé 1974 (BR, K, P, WAG); ibid. loco, 10.V.1963, buds, N. Hallé 1974bis (P); ibid. loco, 6.V.1963, fr., N. Hallé 2001 (K, P). Ngounié: Moukabo, ca 25 km E. of Mouila on the road to Yeno, 27.XI.1984, fl., Arends et al. 468 (BR, LBV, WAG); au N du PN de Waka, 1°09'51"S 11°08'04"E, 24.IX.2007, fr., Boussengui-Nongo et al. 192 (LBV); km 6 Mimongo–Yéno, 21.II.2008, fr., Dessein et al. 2039 (BR, LBV, MO, WAG); Distr. de Mimongo, rte de Lébamba à Etéké km 50, 14.V.1963, fr., N. Hallé & Cours 5873 (P); rte de Lébamba à Etéké km 50, 14.V.1963, fr., N. Hallé & Cours 5874 (BR, P); Rte chantier Leroy-Massika ente Mouila et Yeno, 27.IV.1989, fr., A.M. Louis & Nzabi 3031 (LBV, WAG); Oghoubi camp, on the NE border of Waka National Park, 24.III.2007, fr., Sosef et al. 2529 (BR, LBV, WAG); 25 km on the road Ikobey to Egoubi camp, 1.IV.2004, fr., Wieringa et al. 5203 (BR, LBV, WAG). Nyanga: chantier SFN, Igotchi, 23.XI.2003, fl., van Valkenburg et al. 2604 (LBV, WAG). Ogooué-Ivindo: Masenguelani (60 km SE de Lopé), 30.I.1998, imm.fr., Binot & Lejoly 197 (BRLU); NE du parc de la Lopé, ancienne rte Lopé-Booué, 14 km du carrefour Lopé-Booué, 6.III.2010, fr., Bissiengou et al. 1053 (LBV, WAG); Mintoume, 5.II.2005, fr., Boupoya & Mbazza 186 (BRLU); La Nké, 8.X.1983, fl., Floret et al.1735 (P, WAG); Booué, 31.VII.1966, fl., N. Hallé & Le Thomas 268 (P); Mintome, 30.III.2003, fr., Mboma et al. 61 (LBV, WAG); bac de l’Ogooué, 9.VIII.1983, fl., Sita 4983 (LBV). Ogooué-Lolo: c. 30 km E of Lastoursville, 22.XI.1991, fl., F.J. Breteler & Jongkind 10653 (BR, LBV, WAG); Bambidie, c. 30 km E of Lastoursville, 1.V.1992, fl. & fr., F.J. Breteler et al. 11205 (BR, G, LBV, WAG); Makande surroundings, c. 65 km SSW of Booué, 30.I.1999, imm.fr., F.J. Breteler et al. 14853 (BR, LBV, WAG); Makandé, Débardage Héron, 14.XI.1993, fl., Dhetchuvi et al. 11 (BRLU); Makandé, près de la station, 18.XI.1993, fl., Dhetchuvi 1308 (BR, BRLU, WAG); c. 50 km SE of Achouka, old forest in Région des Abeilles, 16.XI.1983, fr., A.M. Louis et al. 723 (BR, K, P, WAG); Camp Makande, 27.XI.1993, fl., Moungazi 928 (LBV); Forêt des Abeilles, Makandé, just NE of campsite, 12.I.2001, fl., Wieringa et al. 4075 (LBV, WAG); c. 30 km ENE of Lastoursville, east of Bambidie, 5.0 km on CEB exploration road NZ P/2, 22.III.2013, fr., Wieringa et al. 7673 (WAG). Ogooué-Maritime: Monts Doudou, W. of Doussala and Rés. de Faune de Moukalaba, 4.XII.1984, fl., Arends et al. 607 (LBV, WAG). Woleu-Ntem: Montagne Mengong sur rte Sam vers Mitzic, 25.II.1988, imm.fr., A.M. Louis 2688 (LBV, WAG). REPUBLIC OF CONGO. Kouilou: Makaba, ancien village Manengue, 17.II.1987, fr., de Foresta 1291 (P); km 36–38, rte de Sounda à Pointe-Noire, 8.II.1966, fr., Farron 5030 (P); bord de la Loukomba, 19.I.1894, fl., Lecomte D6 (P). Lékoumou: village de Mitsiba, après Moetchè, 24.I.1965, fl., Bouquet 1087 (P)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 132-133, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge.","GOOD, R. D. (1923). New tropical African Rubiaceae. J. Bot. 61: 86 - 87. HALLE, N. (1960). Sur les Cuviera (Rubiacees) d'Afrique intertropi-"]}

3a. Sabicea floribunda var. floribunda (Fig. 7A). Distribution, ecology and phenology. – This taxon occurs in Atlantic Central Africa, mostly from southern Cameroon to east-central Gabon with a disjunct occurrence in southeastern Nigeria and adjacent western Cameroon (Fig. 8). Its distribution marginally overlaps with those of var. paucinervis in the west of its range and of var. anisostegia in the east. It occurs in forest edges and regrowth, often along roads, 0–510 m in elevation, and is locally abundant. Flowers probably all year (recorded from all months except March, June and September); fruits from February to June. Conservation status. – The extent of occurrence (EOO) of S. floribunda var. floribunda is calculated to be 187,299 km ², well above the limit for “Vulnerable” status under subcriterion B 1. Its area of occupancy (AOO) is estimated to be 84 km ², which falls within the limit for “Endangered” status under subcriterion B 2, but is an obvious underestimation, given the low collecting density in most of its range. The taxon occurs in Central Africa from Nigeria to Gabon, and is known from 26 specimens. It is a locally common plant of secondary forest habitats, and not in any way threatened; consequently it is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – This taxon is morphologically (and also geographically) intermediate between S. floribunda var. paludosa and var. paucinervis, differing from the former in the shape and indumentum of its bracts, and from the latter by its stems and leaves being more hairy, the latter with more numerous secondary veins. Additional material studied. – CAMEROON. Reg. South: au S de Zingui, 20.I.1962, fl., Letouzey 4043 (BR, K, P, WAG, YA); Ebemwok (55 km W Ebolowa), 13.III.1963, imm.fr., J. & A. Raynal 10435 (P, YA); Bebai, Campogebiet, 14.XII.1908, buds, Tessmann 716 (K); Bipindi, 1898, buds, Zenker 1820 (BM, G, K, P, WAG); Bipindi, 1904, fl., Zenker 3232 (BM, BR, K). Reg. Southwest: Abonando, 5.V.1902, buds, Rudatis 52 (K). EQUATORIAL GUINEA. Centro-Sur: Monte Mitra, 28.XI.1997, fl., Obama 315 (BRLU, WAG); SE of Bata c. 50 km, Oborobikó, 25.II.1969, fl. (fallen), Sanford 6034 (K); Ayaguening (Akonangui), 11.VIII.2001, buds, Sonké 2518 (BR, BRLU); 8 km N de Mitong, 13.XII.2003, buds, Sonké 3157 (BR, BRLU, K). Litoral: rte d’exploitation chantier SEMGE vers le 1er pont sur Mitemelé, 13.VI.1988, fr., Dibata 451 (BR, K, WAG); de Sendje à Ongamnsok, 19.II.2001, imm.fr., Lejoly 01/08 (BRLU); rte de Nco vers Misobong au niveau de la grande cascade, 9.I.1998, fl., N. Nguema & Lejoly 206 (BRLU). GABON. Estuaire: Forêt de Mondah on road Libreville-Cap Esterias, 26.II.1999, imm.fr., Andersson & Nilsson 2277 (BR); c. 20 km NNE of Libreville, 11.III.1987, fr., J.M. Reitsma & B. Reitsma 3142 (LBV, WAG); Crystal Mountains N.P., 8 km on road from Kinguélé to Tchimbélé, 26.III.2013, imm.fr., Wieringa et al. 7801 (WAG). Moyen-Ogooué: Mboumi. 0°18–0°30S/10°45–10°48E, 16.I.2000, fl., Champluvier 6019 (BR, K, WAG). Ogooué-Lolo: Chantier Bambidie, c. 52 km on the road to Okondja-Lelama, along Sebe river, 31.X.2005, fl., Sosef et al. 2122 (BR, LBV, WAG). OgoouéMaritime: Région du Lac Alombié, ± 7 km au N de Mpaga, 18.X.2014, buds, Lachenaud et al. 2007 (BRLU, LBV, MO). Woleu-Ntem: SEEG road near Tchimbélé, pylone 7, 6.II.2008, buds, Dessein et al. 1724 (BR, LBV, WAG); Angoum, 28.VII.1933, fl., Le Testu 9198 (BM, P); Monts de Crystal, Tchimbélé, 14.IV.2006, imm.fr., Leal et al. 1109 (BR, LBV). NIGERIA. Cross River State: Oban, 1911, buds, Talbot 228 (BM, K); New Ndebiji, 30.IV.1952, fl., Ejiofor FHI 21883 (FHI, K)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 126-129, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge."]}

7a. Sabicea sanguinosa subsp. sanguinosa (Fig. 2E–F, 12E). Distribution, ecology and phenology. – This subspecies is endemic to coastal Gabon, occurring in the Wonga-Wongué reserve and slightly further north (Nyonié) (Fig. 10) and grows in forest edges on coastal sandy soils, up to 150 m in elevation. Flowers collected in January (buds), February, and from May to July; fruits in January-February and August. Conservation status. – The extent of occurrence (EOO) of S. sanguinosa subsp. sanguinosa is estimated to be 860 km ², and its area of occupancy (AOO) to be 32 km ²; both values fall within the limit for “Endangered” status under subcriteria B 1 and B 2. The taxon is endemic to coastal Gabon, and is known from nine specimens, representing five subpopulations, all but one of which occur in the Wonga-Wongué Presidential Reserve. Its situation is rather comparable to that of the species as a whole, and it is assessed as “Least Concern” [LC] for the same reasons using the IUCN Red List Categories and Criteria (IUCN, 2012). Additional material studied. – GABON. Estuaire: Savane Boyam, 25.I.1997, fl.b., Delègue 1.Trs (LBV); Oyane, X.1990, st., Minkoue 55 (LBV); Réserve de Wonga Wongué, 23.I.1986, fr., A.M. Louis & J.M. Reitsma 2004 (LBV, WAG); Nyonyie survey, sondage W, 28.VI.1990, fl., Wilks 2028 (WAG); Nyonyie, Transect M2, 15.VII.1990, fl., Wilks 2252 (WAG). Moyen-Ogooué: Eastern part of the Presidential Reserve Wonga-Wongué, c. 100 km S of Libreville, 28.II.1983, fl. & fr., J.J.F.E. de Wilde et al. 815 (BR, K, LBV, WAG). OgoouéMaritime: à ± 10km au SSE de Batanga, 21.V.2001, fl., Sosef 1613 (K, LBV, P); ca 10 km à l’Est de Batanga, 26.V.2001, fl., Sosef 1745 (K, LBV, P)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 138-140, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge."]}

1. Sabicea couteronii O. Lachenaud, Zemagho & Sonké, sp. nov. (Fig. 1A–B, 3, 6A–C). Holotypus: CAMEROON. Reg. South: 13 km E Sangmelima, 24.V.2016, fl., Sonké & Zemagho 6341 (BR!; isotype: BRLU!, K!, MO!, WAG!, YA!). Habitu sarmentoso, ovario biloculare, foliis valde discoloribus subtus indumento denso lanato et persistente munitis, corolla fauce pilis brevibus inflatis munita S. nobile similis, a quae differt ramis et foliis subtus ad nervis indumento mixto pilis lanatis et rectis (nec pilis omnibus lanatis) munitis, inflorescentiis ad anthesim breviter ramosis (nec capitatis), fructibus rubro-purpureis deinde nigrescentibus (nec albis), seminibus grosse reticulatis (nec striolatis). Sarmentose liana, c. 3 m high; stems cylindrical, 3.5 – 6 mm thick, covered with a dense buff indumentum of straight ± appressed hairs c. 1.5 mm long, intermingled with shorter crispate hairs. Stipules interpetiolar, pale green, 10 – 15 × 4– 12 mm, erect, ovate and longitudinally plicate (except on buds), truncate at base, gradually acuminate at apex, uniformly pubescent outside with same indumentum as the stems, more sparsely so inside. Leaves opposite, slightly unequal; petiole (1–) 1.8–5 cm long, with same indumentum as the stems; lamina (9–)10.7–19.3 × (3.8–) 5.8–10.3 cm, elliptic to ovate, obtuse to rounded at base, gradually acuminate at apex, slightly coriaceous, discolorous; upper side dark green, densely pubescent on the veins with same indumentum as the stems, very sparsely so between them; margin densely ciliate with appressed hairs; lower side pale buff, with dense woolly hairs covering most of the surface (sparser on old leaves), and long straight hairs on the veins; secondary veins 13–16 pairs, weakly to moderately ascending, eucamptodromous; tertiary veins raised on the lower leaf surface and distinctly more prominent than quaternary veins, the latter densely reticulate but ± hidden by indumentum. Inflorescences axillary, paired at nodes or sometimes solitary, densely cymose, many-flowered, 1.7–5 cm long, densely pubescent with same indumentum as the stems; peduncle 0.5–2.5 cm long; primary ramifications 0.3–1 cm long. Bracts green, free, pubescent on both sides, all recaulescent except the basal pair; basal bracts broadly ovate, 7.5–12 × 5– 6 mm, entire or dentate, acute at apex; median bracts broadly ovate, 6 –14 × 3– 7 mm, entire, acute to obtuse at apex; upper bracts narrowly elliptic, 3– 6 × 0.8– 2 mm, entire, acute at apex. Flowers 5-merous; pedicels 0–1 mm long, densely villose. Calyx pale green; tube c. 1 mm long, densely villose on both sides; lobes elliptic to obovate, 1.5–2.5 × 0.8–1.5 mm, obtuse and curved outwards at apex, villose on both sides, alternating with minute colleters. Corolla white; tube cylindrical or nearly so, 4–5 × 1–1.5 mm, outside mostly glabrous but sparsely appressed-pubescent at apex, inside pubescent from the upper ¼ TH to the throat, the latter with short inflated unicellular hairs; lobes triangular, c. 1.3 × 1.3 mm, patent, pubescent with stiff appressed hairs outside, glabrous inside; flower buds obtuse, slightly enlarged at apex. Stamens included, attached around the upper ¼ TH of the corolla tube; anthers sessile, elliptic, 0.75–1 × 0.25–0.4 mm, glabrous. Ovary 1.5–2 mm long, densely villose, 2-locular. Disk cylindrical, c. 0.7 mm long, glabrous, shorter than the calyx tube. Style 4–4.5 mm long, just reaching the corolla throat, glabrous, bifid, with shortly stipitate elliptic flattened stigmas c. 1 mm long. Fruits purplish-red when young, blackish when mature, ellipsoid, with persistent calyx, 8– 11 × 7– 9 mm in life, 6–9 × 4.5–8 mm when dry, villose, with pedicel c. 1 mm long; mesocarp very soft, purple, c. 1.5 mm thick, with numerous darker granules. Seeds numerous, dark brown, polyedric, c. 0.6 × 0.4 mm, the surface rather coarsely reticulate. Etymology. – The species is named after Dr Pierre Couteron (Institut de Recherche pour le Développement, Montpellier, France) in recognition for his constant support to the second and third authors. Distribution, ecology and phenology. – Sabicea couteronii has an apparently very scattered distribution (Fig. 4), being known from one locality in south Cameroon (near Sangmelima), one in central Gabon (Waka National Park) and two in southwestern Republic of Congo (Mayombe and Chaillu massifs). It occurs in secondary forest, edges and regrowth, c. 685 m in elevation (probably also lower). Flowers have been collected in May-June, fruits in November and January (immature) and June (mature). Conservation status. – The extent of occurrence (EOO) of S. couteronii is calculated to be 73,728 km ², exceeding the limit for “Vulnerable” status under subcriterion B 1, while its area of occupancy (AOO) is estimated to be 16 km ², within the limit for “Endangered” status under subcriterion B 2. The species occurs in Atlantic Central Africa (Cameroon, Gabon and Republic of Congo) and is known from six specimens, representing four subpopulations. Two of them occur in protected areas, Waka National Park in Gabon and Dimonika Biosphere Reserve in Congo. The other two subpopulations occur along roads, and the Cameroonian one at least is threatened by habitat destruction due to agricultural activities. A decline in habitat extent and quality and number of individuals is therefore expected. The four subpopulations represent four locations in the sense of ICUN (2012), and the species qualifies for “Endangered” [EN B 2ab(iii,v)] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – Sabicea couteronii resembles both S. nobilis and S. proselyta, which both occur in its range, and at first sight might be suspected to be a hybrid between them; this is however unlikely, as it differs from both by the colour of its fruits, which are purplish-red when young and blackish when mature (vs. white or greyish-white). It is further separated from S. proselyta by its strongly discolorous leaves with dense woolly indumentum below (Table 1), and from S. nobilis by its (shortly) branched inflorescences, reticulate seed surface, and the presence of long silky hairs (in addition to woolly ones) on the stems, petioles and underside of the leaf veins. The specimens from Gabon and Congo are either vegetative (Cusset 875) or with immature fruits (Boussengui-Nongo et al. 309, Kimpouni 600) but match very well the Cameroonian material, differing only in the longer peduncles (probably not a very significant character), and, in the case of the Gabonese material, sparser indumentum of the lower leaf surface (probably because the leaves are older). Therefore, we regard them as conspecific. Kimpouni 600 was previously cited as Pseudosabicea proselyta (LACHENAUD, 2009) of which it was the only record from the Republic of Congo; however, authentic Congolese specimens of S. proselyta have since been found (see that species). It is not known if S. couteronii is heterostylous; only the type specimen bears flowers, which are of the long-styled form. Paratypi. – CAMEROON. Reg. South: 13 km E Sangmelima, 28.VI.2015, fr., Sonké 6248 (BR, BRLU, K, MO, WAG, YA); ibid. loco, 16.V.2016, fr., Sonké & Zemagho 6334 (BR, BRLU, K, MO, WAG, YA). GABON. Ngounié: Parc national de Waka, 1°10'34"S 11°08'02"E, 28.XI.2007, imm.fr., Boussengui-Nongo et al. 309 (LBV). REPUBLIC OF CONGO. Kouilou: env. de Dimonika, source Paris Sangha, 5.III.1980, ster., Cusset 875 (P). Niari: Rte Komono–Mossendjo, 2 km du camp SIDETRA, 8.I.1989, imm.fr., Kimpouni 600 (BRLU)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 121-122, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge.","LACHENAUD, O. (2009). La flore des plantes vasculaires de la Republique du Congo: nouvelles donnees. Syst. Geogr. Pl. 79: 199 - 214."]}

3b. Sabicea floribunda var. anisostegia O. Lachenaud, Zemagho & Sonké, var. nov. (Fig. 1E–F). Holotypus: CAMEROON. Reg. East: près Yenga Port Gentil, village situé à 35 km au NNE de Moloundou, 21.IV.1971, fl., Letouzey 10716 (BR!; isotype: K!, P!, YA!). Ab alteribus varietatibus differt bracteis valde inaequales majoribus in inflorescentia dispersis (nec bracteis superioribus gradualiter minoribus quam inferioribus). Etymology. – The varietal epithet anisostegia refers to the bracts of very unequal sizes, which are the main diagnostic character of this taxon. Distribution, ecology and phenology. – This variety occurs from southeastern Cameroon to southwestern D. R. Congo, and disjunctly in eastern D. R. Congo (Fig. 8), but is mostly absent from the central depression of the Congo basin (“cuvette congolaise”) where replaced by var. paludosa. Its range closely approaches that of the latter in both Gabon and D. R. Congo, and locally overlaps that of var. floribunda in Gabon. It is found in forest edges and regrowth, 180–1250 m in elevation. Flowers have been recorded from October to January and April to July, probably all year; fruits from January to July and in September-October, probably all year as well. Conservation status. – The extent of occurrence (EOO) of S. floribunda var. anisostegia is calculated to be 1,349,092 km ², well above the limit for “Vulnerable” status under subcriterion B 1. Its area of occupancy (AOO) is estimated to be 124 km ², which falls within the limit for “Endangered” status under subcriterion B 2, but is an obvious underestimation, given the low collecting density in most of its range. The taxon occurs in Central Africa from Cameroon to the Democratic Republic of Congo, where it grows in secondary forest, and is known from 40 specimens. Its situation is rather comparable to that of the species as a whole, and it is assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012) for the same reasons. Notes. – This is the most distinctive variety of S. floribunda, and further work may show it to be specifically distinct. It is best recognised by the arrangement of the bracts in the inflorescence: var. anisostegia has a few large bracts occurring at scattered nodes and the remainder much smaller, while in other varieties the bracts are more or less gradually decreasing in size from lower to upper nodes (except the lowest pair, which is often smaller than those above it). It is also usually more hairy than other varieties, especially on the stems. Paratypi. – ANGOLA. Cabinda: near the village Caio in the Hombe country, 9.I.1917, fl. & imm.fr., Gossweiler 7665 (BM, K). CAMEROON. Reg. Central: Réserve forestière Mbalmayo, 15.IV.1967, fl., Mezili 80 (BR, P); Atotzok, 1953, fl. & imm.fr., Surville 312 (YA). Reg. East: 22 km E of Lomié, 12.II.1977, fr., Lowe 3149 (K, YA); Near Echiambor, 18.II.1977, fr., Lowe 3500 (YA); Nkamouna, 11.VI.2004, fl., Sonké 3481 (BR, BRLU); ibid. loco, 11.VI.2004, fr., Sonké 3482 (BR, BRLU); Mbalam II: Mbarga, 24.VI.2008, fl., Sonké 4943 (BR). Reg. South: Bitye, 1917, fl., Bates 885 (BM); Bitye, 1917, buds, Bates 1120 (BM); à l’W d’Alati (100 km SE de Djoum), 12.I.1973, imm.fr., Letouzey 11832 (BR, P, YA). DEMOCRATIC REPUBLIC OF CONGO. Ituri: Ituri, Lodjo, near AGK mining camp, 25.I.2011, imm.fr., Bytebier et al. 3343 (BR); Ituri, mont Hoyo, 2.VIII.1975, imm.fr., Lisowski 40879 (BR). Kongo Central: Kimuenza, X–XI.1900, fl., Gillet 1749 (BR); Entre Luzumu et Sanda, vallée de la Ma Ngo, 25.II.1965, fr., Pauwels 4905 (BR). Nord-Kivu: entre Walikale et Kalehe (Kivu), III.1932, fl. & imm.fr., Lebrun 5267 (BR, WAG); Rte Kavumu-Walikale, vers km 110, env. d’Irangi, 11.III.1960, fr., Troupin 12067 (BR). Tshopo: km 58, rte de Kisangani vers Ubundu (rive gauche), 6.IV.1977, fr., Lejoly 1278 (BR, BRLU); rte Kisangani-Ubundu, km 58, 7.IV.1977, fr., Lisowski 44605 (BR, K). GABON. Haut-Ogooué: 5 km rte Moanda-Bakoumba, 16.IX.1970, fr., F.J. Breteler 6475 (BR, K, LBV, P, WAG); de Zanaga à Franceville, 21.X.1954, fl., Trochain 9099 (P). Ogooué-Ivindo: 7 km N of km 49 Makokou-Mekambo road which is bifurcation with Bélinga road, near Djadie R., 15.XI.1977, fl., Leeuwenberg 11545 (BR, K, P, WAG); Babièl-Nord ridge, 4 km from camp Bélinga, X.1987, fl., A.M. Louis et al. 2312 (BR, LBV, WAG); Rte de Babiel Nord, few km W of Belinga, 18.VII.1985, fl. & imm.fr., Bos et al. 10658 (BR, K, LBV, P, WAG); Bélinga, 9.VI.1978, fr., Florence 1217 (P); Belinga, 25.VII.1981, fr., Gentry 33569 (P); piste du Bouéni, 20 km SE Makokou, 11.II.1961, fr., N. Hallé 1130 (K, P); 7 km NE Makokou, 11.III.1961, fr., N. Hallé 1454 (P); Bélinga, 26.X.1964, fl., N. Hallé 2804 (K, P); ibid. loco, 28.X.1964, buds, N. Hallé 2866 (BR, P); ibid. loco, 31.X.1964, fl. & fr., N. Hallé 2951 (BR, K, P); ibid. loco, 11.XI.1964, buds, N. Hallé 3126 (P); ibid. loco, 1.I.1980, fl., Pierre-Baltus 98 (P); 25 km on road Mékambo to Madjingo, 27.XII.2000, fl., Wieringa et al. 3648 (BR, LBV, WAG). Ogooué-Lolo: Chantier Bambidie, c. 52 km on the road to Okondja-Lelama, along Sebe river, 31.X.2005, fr., Sosef et al. 2123 (LBV, WAG). Woleu-Ntem: behind the WWF-station, at entrance to Bordamur consession area, 8.X.2002, fr., Strijk 54 (WAG); ibid. loco, 1 km from Assock Begue, 8.X.2002, fl., Strijk 59 (LBV, WAG). REPUBLIC OF CONGO. Bouénza: forêt de la Bouénza, piste de l’Espérance du village de M’Boumou vers la Bouénza, 16.XI.1964, buds, Bouquet 757 (P). Sangha: West slope of Mt. Nabemba, 15.XI.1991, buds, Thomas et al. 8892 (WAG).

3c. Sabicea floribunda var. paludosa O. Lachenaud, Zemagho & Sonké, var. nov. Holotypus: DEMOCRATIC REPUBLIC OF CONGO. Tshopo: Lilanda (Yangambi), 15.VIII.1940, fl., Germain 449 (BR!; isotype: K!). Ab alteribus varietatibus differt bracteis ± obovatis utrinque dense pubescentibus (nec orbicularibus, ovatis vel late ellipticis, glabris vel pilis sparsis munitis). Etymology. – The epithet paludosa refers to the fact that this taxon is most commonly found in swamp and riverine forests, while other varieties usually grow on drained soils. Distribution, ecology and phenology. – This taxon occurs in northeastern Gabon, and in D. R. Congo where it is found mostly in the central depression of the Congo basin (“cuvette congolaise”) with isolated records further east (Kivu) and south (near the border with Angola) (Fig. 8). Its range closely approaches that of var. anisostegia in both Gabon and D. R. Congo. It grows mostly in swamp and riverine forest, but apparently also in secondary forest regrowth on drained soils, 350–1000 m in elevation. Flowers have been recorded in January, from April to June and from August to October; fruits from April to October. Conservation status. – The extent of occurrence (EOO) of S. floribunda var. paludosa is calculated to be 759,404 km ², well above the limit for “Vulnerable” status under subcriterion B 1. Its area of occupancy is estimated to be 64 km ², which falls within the limit for “Endangered” status under subcriterion B 2, but is an obvious underestimation, given the low collecting density in most of its range. The taxon occurs in eastern Gabon and the Democratic Republic of Congo, and is known from 21 specimens representing 15 subpopulations, one of which occurs in a protected area (Kahuzi-Biega National Park in D. R. Congo). It is found in swamp forest and secondary forest regrowth, and appears to be not rare in its range. Given its ecology and wide distribution there is no evidence of a particular threat, and it is here assessed as Least Concern [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – This taxon differs from other varieties by its more or less obovate and densely pubescent bracts (vs. orbicular, ovate or broadly elliptic, with indumentum sparse or absent) which are also usually narrower in proportion – hence a similarity with S. segregata, but that species does not occur in its range. In all other characters, especially leaves and indumentum, it comes very close to var. floribunda. Paratypi. – DEMOCRATIC REPUBLIC OF CONGO. Bandundu: Iküma, 13.X.1948, fl., Jans 807 (BR). Equateur: Ikelemba, VI.1934, fl., Dubois 423 (BR); rte Bikoro-Inongo, km 27, 17.X.1957, imm.fr., Evrard 2674 (BR); rte Flandria-Makako (territoire Ingende), 9.IV.1959, fl., Evrard 6054 (BR); Bondombe, 9.IX.1942, buds, Hulstaert 843 (BR); Lac Tumba-I.R.S.A.C. Mabali, 20.VI.1958, imm.fr., Thonet 221 (BR, K). Kwango: entre Popokabaka et Kimabaka, près rivière Pumbu, 18.IV.1959, fl., Pauwels 2495 (BR, P). Kwilu: vallée de la Djuma, VII.1902, imm.fr., Gentil s.n. (BR); région de Bampumu, X.1922, fl., Vanderyst 12481 (BR). Sud-Kivu: Kiaselela, territoire Shabunda, 19.IV.1959, imm.fr., A. Léonard 3900 (BR, P). Tshopo: Opala, 15.VI.1949, imm.fr., Germain 5116 (BR, WAG); Yabahondo (rive gauche du Lomami), 15.X.1952, fl. & imm.fr., Germain 8116 (BR); Yangambi, 3.VI.1958, imm.fr., A. Léonard 759 (BR, K); env. de Kisangani, à 3 km à l’E de Kabondo, 24.X.1977, buds, Lisowski 47453 (BR, K); Kisangani, Kabondo, 6.V.1979, fl. (fallen), Lisowski 52401 (BR, K); 20 km à l’W de Yangambi, 27.X.1938, fl., J. Louis 12110 (BR). Tshuapa: Befale, IX.1934, imm.fr., Dubois 767 (BR); Befale-Tolongote, 5.VI.1958, fl., Evrard 4185 (BR, K, WAG). Sine loco: sine loco, s.d., fl., Pauwels 660 (BR). GABON. Ogooué-Ivindo: 10 km on road Malassa to Madouma, 8.I.2001, fl., Wieringa et al. 4028 (LBV, WAG)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 129-130, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge."]}

5. Sabicea proselyta (N. Hallé) Razafim. et al. in Taxon 57: 20. 2008 (Fig. 2A–B, 7E–F). ≡ Pseudosabicea proselyta N. Hallé in Adansonia ser. 2, 3: 172. 1963. Holotypus: GABON. Estuaire: Nkoulounga, 11.VII.1959, N. Hallé 748 (P [P00077595]!). Distribution, ecology and phenology. – Sabicea proselyta occurs in southern Cameroon, Equatorial Guinea (Rio Muni), western and central Gabon (but not in the lower Ogooué basin) and the Mayombe range in southwestern Republic of Congo (Fig. 10). It grows in secondary forest, edges and regrowth, on drained soils or sometimes along rivers, 50–1080 m in elevation. Flowers have been collected in April, June-July and November; fruits in January (immature), February to May (mature), July (immature) and November (mature). Conservation status. – The extent of occurrence (EOO) of S. proselyta is calculated to be 162,301 km ², well above the limit for Vulnerable status under subcriterion B 1. Its area of occupancy (AOO) is estimated to be 92 km ², within the limit for “Endangered” status under criterion B 2, but is evidently underestimated because most of its range is not well prospected. The species occurs in Central Africa from south Cameroon to the Congo Republic, and is known from 28 specimens representing 22 subpopulations. It occurs in four protected areas, the Monte Alén National Park in Equatorial Guinea, Waka and Doudou Mountains National Parks in Gabon, and Dimonika Biosphere Reserve in the Republic of Congo. Most of its range is sparsely populated, and because it is a plant of forest edge habitats, it is likely to benefit from small-scale forest clearing, e.g. that induced by selective logging. As a result there is no evidence of a particular threat, and the species is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – Although the protologue (HALLÉ, 1963) does not specify in which herbarium the type of S. proselyta was deposited, this collection has only one sheet in P, which is therefore considered as the holotype. Probably because Sabicea proselyta has no very striking characters, it has often been confused with its relatives S. couteronii, S. dichrosepala, S. rubiginosa and S. sanguinosa. The differences between them are summarised in Table 1. Among the 18 Gabonese specimens cited as Pseudosabicea proselyta by SOSEF et al. (2006), only nine are correctly identified; six belong to S. rubiginosa (Breteler 9576; Haegens 222; van Nek 128 & 190; Wieringa 2389; J. J. F. E. de Wilde 9688), one to S. dichrosepala (J. J. F. E. de Wilde 284) and two to S. sanguinosa subsp. sanguinosa (Sosef 1613, 1745). Another collection from the Republic of Congo, Kimpouni 600, cited by LACHENAUD (2009) as Pseudosabicea proselyta, actually represents S. couteronii. The two collections from the Republic of Congo cited here are therefore the first authentic records of S. proselyta from this country. The indumentum of the lower leaf surface is usually appressed in this species, but in two collections (J. J. F. E. de Wilde 7762 from Cameroon and van Valkenburg et al. 3140 from Gabon) it is mostly erect with appressed hairs restricted to the veins. These collections match S. proselyta in other characters and are therefore regarded as conspecific. Additional material studied. – CAMEROON. Reg. South: station du Cacaoyer de N’koemvone, S. of Ebolowa, 14 km on the road to Ambam, 28.XI.1974, fl. & fr., J.J.F.E. de Wilde 7762 (BR, K, P, WAG, YA); E Sangmelima, 16.V.2016, fr., Sonké & Zemagho 6329 (BR, BRLU, K, MO, WAG, YA); Campo Ma’an area, Onoyong, in the National Park, 20.III.2001, imm.fr., Tchouto Mbatchou et al. ONOX 93 (WAG). EQUATORIAL GUINEA. Centro-Sur: Monte Alen, 25.III.1997, fr., Ngomo 78 (BRLU); Monte Alen, Transecto 3,900 m del transecto, 21.VII.1998, imm.fr., Ngomo & Ndong 368 (BRLU); PN de Monte Alen, dalle rocheuse d’Engong, 5 km à l’W du village d’Engong, 12.V.2002, fr., Parmentier & Esono 2780 (BRLU); PN de Monte Alen-transect de Monte Chocolate, 8.I.1998, imm. fr., Van Reeth 141 (BRLU). Litoral: Rte de Nco vers Misobong au niveau de la grande cascade, 9.I.1998, imm.fr., N. Nguema & Lejoly 202 (BRLU). Wele-Nzas: entre Nsuamayong et inselberg Akuom, 23.I.1998, imm.fr., Obama & Lejoly 656 (BRLU). GABON. Estuaire: km 18 Kougouleu-Kouamé road, 15.XI.1982, fl., Leeuwenberg 12511 (BR, K, LBV, WAG); km 13 Tchimbélé-Kinguélé, 7.II.2008, fr., Dessein et al. 1747 (BR, LBV, WAG); Monts de Cristal, 5 km de Kinguélé, 18.I.1968, imm.fr., N. Hallé & Villiers 4540 (P); Crystal Mountains, 250 m on transect D 4, 25.XI.2000, fl., N. Nguema 1459 (BR, LBV, WAG). Moyen-Ogooué: Mboumi, 16.II.2000, imm.fr., Champluvier 6163 (BR, K); c. 10 km NNW of Ndjolé, on BSO forestry road, 26.II.2008, fr., Dessein et al. 2150 (BR, LBV, WAG); C.E.F.A. Ayem, 10 km SW Ndjolé, 29.IV.1963, fr., N. Hallé 1918 (K, P); ibid. loco, 29.IV.1963, buds, N. Hallé 1918bis (BR, K, P); ibid. loco, 30.IV.1963, fl., N. Hallé 1955 (K, P); ibid. loco, 8.V.1963, fr., N. Hallé 2022 (P); Abanga, chantier CEFA, 1.VI.1963, fl., N. Hallé 2126 (P). Ngounié: Parc national de Waka, 1°10'34"S 11°08'02"E, 28.XI.2007, imm. fr., Boussengui-Nongo et al. 312 (LBV); Ovala, 16.V.1963, fr., N. Hallé & Cours 5937 (P). Nyanga: chantier SFN, 28.XI.2003, fl. & imm.fr., van Valkenburg et al. 2646 (BR, K, LBV, P, WAG). Ogooué-Maritime: logging road CBG concession eastward of Peni, 20.IV.2005, fr., van Valkenburg et al. 3140 (BR, K, WAG). Woleu-Ntem: 15 km SE of Mitzic, FOREENEX forest exploitation, road from FOREENEX forestry camp to Madouaka village, 7.XI.2009, fl., Bissiengou et al. 752 (LBV, WAG). REPUBLIC OF CONGO. Kouilou: rte de Dimonika à Pounga, 24.XI.1978, fl., Cusset 514 (P). Niari: Col du Bamba, 6.I.1969, imm.fr., Attims 58 (P)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 133-134, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge.","HALLE, N. (1963). Delimitation des genres Sabicea Aubl. et Ecpoma K. Schum. en regard d'un genre nouveau: Pseudosabicea (Mussaendeae-Rubiaceae). Adansonia ser. 2, 3: 168 - 177.","SOSEF, M. S. M., J. J. WIERINGA, C. C. H. JONGKIND, G. ACHOUNDONG, Y. AZIZET ISSEMBE, D. BEDIGIAN, R. G. VAN DEN BERG, F. J. BRETELER, M. CHEEK, J. DEGREEF, R. B. FADEN, P. GOLDBLATT, L. J. G. VAN DER MAESEN, L. NGOK BANAK, R. NIANGADOUMA, T. NZABI, B. NZIENGUI, Z. S. ROGERS, T. STEVART, J. L. C. H. VAN VALKENBURG, G. WALTERS & J. J. F. E. DE WILDE (2006). Checklist des plantes vasculaires du Gabon. Checklist of Gabonese vascular plants. Scripta Bot. Belg. 35.","LACHENAUD, O. (2009). La flore des plantes vasculaires de la Republique du Congo: nouvelles donnees. Syst. Geogr. Pl. 79: 199 - 214."]}

7b. Sabicea sanguinosa subsp. viridis O. Lachenaud, Zemagho & Sonké, subsp. nov. (Fig. 12F, 13A–B). Holotypus: GABON. Ogooué-Maritime: région du Lac Alombié, ± 7 km au N de Mpaga, 0°50'20"S, 9°27'14"E, 14.X.2014, fl. & fr., Lachenaud, Ikabanga & Lafferty 1918 (BRLU!; isotype: BR!, G!, LBV!, MO!, P!, WAG!). A typo differt calycis bracteisque pallide viridibus, nec atrorubris. Distribution, ecology and phenology. – This subspecies is endemic to the lower Ogooué delta in Gabon, between the coast and Lake Alombié (Fig. 10); it has thus a more southern range than subsp. sanguinosa. It occurs in the same habitat as the latter, and is locally very abundant. Flowers recorded in October-November, fruits in October (probably in other months as well). Conservation status. – The extent of occurrence (EOO) of S. sanguinosa subsp. viridis is estimated to be 483 km ², and its area of occupancy (AOO) to be 16 km ², both values being within the limit for “Endangered” status under subcriteria B 1 and B 2. The taxon is endemic to the Ogooué delta in Gabon, and is known from five specimens, representing four subpopulations. It is not known from any protected area, but probably occurs in the Wonga-Wongué Presidential Reserve since it has been collected very close to its limits. In spite of its restricted range, it occurs in a sparsely populated area, and is a locally abundant plant of forest edge habitats, which benefits from small-scale forest clearing (e.g. that induced by selective logging). As a result, there is no evidence of a particular threat, and the taxon is assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria (IUCN, 2012). Paratypi. – GABON. Ogooué-Maritime: Préfecture de M’paga, à env. 7 km au N du lac Alombié, au S de la réserve de Wonga Wongué, 11.X.2014, fl. & fr., Bidault et al. 1691 (BR, BRLU, MO, P); delta de l’Ogooué en face de Port-Gentil, au S de la Pointe Fétiche, 22.XI.2016, fl., Lachenaud et al. 2270 (BR, BRLU, G, K, LBV, MO, P, WAG); env. 5 km au SE de Mbilapé, 24.XI.2016, fl., Lachenaud et al. 2314 (BR, BRLU, G, LBV, MO, P, WAG); riv. de Kendié en aval de Mbilapé, rive E, 25.XI.2016, fl., Lachenaud et al. 2335 (BR, BRLU, LBV, MO, WAG)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on page 140, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge."]}

2. Sabicea dichrosepala O. Lachenaud, Zemagho & Sonké, sp. nov. (Fig. 1C–D, 5, 6D–E). Holotypus: GABON. Ngounié: km 43 Mouila–Yéno, 21.II.2008, Dessein et al. 2028 (BR [BR0000013945923]!; isotype: LBV!, WAG!). Habitu sarmentoso, ovario biloculare, seminibus grosse reticulatis, foliis utrinque viridibus subtus ad nervis indumento albido valde appresso munitis, corollaque fauce pilis brevibus inflatis munita S. proselyta similis, a quae differt calyce bicolore apice viride et basi rubro-vinaceo (nec omnino viride), inflorescentiis ad anthesim glomerulatis deinde cymosis (nec semper laxe cymosis), pedunculis nullis vel brevissimis usque 0.3 cm longis (nec 0.7–3.8 cm longis), stipulis basi auriculatis et extus sparsissime pubescentibus (nec basi rotundatis et extus ± dense pubescentibus), foliis subtus venulis tertiariis conspicuis sed haud prominentibus, fructuque albissimo (nec albo-griseo) mesocarpio granulis atris nec munito. Sarmentose liana, 2–4 m high; stems cylindrical, 2–3 mm thick, densely covered with straight whitish appressed hairs c. 1 mm long, intermingled with shorter uncinate hairs. Stipules interpetiolar, pale green, 9–14 × 6–9 mm, erect, ovate and longitudinally plicate (except on buds), slightly auriculate at base, acute or acuminate at apex, minutely and very sparsely appressed-pubescent outside (except the base with indumentum similar to the stems), sparsely villose inside. Leaves opposite, often slightly unequal; petiole 1–5 cm long, with same indumentum as the stems; lamina 8 – 16 × 3.5–9 cm, elliptic to ovate, acute to subcordate at base, gradually acuminate at apex, papyraceous, discolorous; upper side medium green, minutely and sparsely appressed-pubescent to glabrous (except for the midrib which often has longer hairs); lower side pale green with ± orange-tinged secondary veins, minutely and sparsely appressed-pubescent, more densely so on the veins; margin densely ciliate with appressed hairs; secondary veins 13– 19 pairs, weakly ascending, forming inconspicuous loops near the margin; tertiary veins conspicuous but not or hardly raised on lower leaf surface, slightly more prominent than quaternary veins, the latter densely reticulate forming areolae c. 0.5 mm in diameter. Inflorescences axillary and paired at nodes, manyflowered, glomeruliform and 1.2–2.5 cm in diameter at anthesis, becoming laxer and conspicuously cymose, 2.5–3 cm long in the fruiting stage, densely pubescent with stiff appressed whitish hairs 0.5– 0.7 mm long; peduncle 0–0.3 cm long; primary ramifications not or hardly distinct at anthesis, c. 0.5 cm long in the fruiting stage. Bracts green, free, shortly pubescent on both sides, all recaulescent except the basal pair; basal bracts ovate, lobed at base, 7–8.5 × 2.5–4 mm; median bracts elliptic to obovate, 5–6 × 1–2 mm, entire; upper bracts narrowly elliptic to linear, 1.7–4 × 0.25–0.5 mm, entire. Flowers 5-merous; pedicels 0–1 mm long at anthesis, pubescent like the inflorescence. Calyx dark pinkish-red at base and green at apex; tube 0.7–1 mm long,] appressed-pubescent outside and more sparsely so inside; lobes obovate to elliptic, 2.5–4 × 1.5–2.3 mm, somewhat unguiculate at base, obtuse to acute and curved outwards at apex, covered on both sides with short patent hairs, and alternating with minute colleters. Corolla tube wine red, cylindrical, 5 × 1.5 mm, outside glabrous at base and sparsely puberulous in the upper half, inside with a ring of multicellular hairs around the upper third and short, inflated unicellular hairs at the throat, the intervening zone glabrous; lobes cream on both sides, triangular, 1.5 × 1.5 mm, reflexed, sparsely puberulous outside, inside with short inflated unicellular hairs at base and glabrous at apex; flower buds obtuse, slightly enlarged at apex. Stamens included, inserted around upper ¼TH of the corolla tube with their tips just reaching throat; filaments c. 0.4 mm long; anthers cream, elliptic, c. 1.2 × 0.7 mm, glabrous. Ovary c. 1.5 mm long, densely covered with stiff appressed whitish hairs, 2-locular. Disk cylindrical, c. 0.5 mm long, glabrous, shorter than the calyx tube. Style c. 3.5 mm long, included, bifid, with elliptic flattened stigmas c. 1 mm long, these shortly stipitate. Fruits white, ellipsoid, with persistent calyx, 5–7 × 4–6 mm when dry, sparsely pubescent with appressed hairs, on accrescent pedicel 4–6.5 mm long; mesocarp very soft, entirely white (without darker granules). Seeds numerous, dark brown, polyedric, c. 0.5 × 0.3 mm, the surface prominently and rather coarsely reticulate. Etymology. – The species epithet refers to the bicoloured calyx lobes, which are the plant’s most striking character in the field. Distribution, ecology and phenology. – Sabicea dichrosepala is apparently endemic to Gabon, where it occurs in the Cristal Mountains in the northwest and the Chaillu massif in the south (Fig. 4), two areas well-known for their endemism and floristic affinity. It might be expected in adjacent parts of Equatorial Guinea and the Republic of Congo. Although probably under-collected, it is clearly an uncommon species. It occurs in forest edges, especially along tracks or forest streams, 610–730 m in elevation. Flowers have been collected in January-February (buds) and March (open); fruits in September (immature), February and March (mature). Conservation status. – The extent of occurrence (EOO) of Sabicea dichrosepala is estimated to be 17,016 km ², and its area of occupancy (AOO) to be 28 km ², respectively within the limits for “Vulnerable” and “Endangered” status under subcriteria B1 and B2. The species is endemic to Gabon and is known from seven specimens, representing six subpopulations, one of which occurs in a protected area, the Crystal Mountains National Park. The species occurs in sparsely populated areas, and favours forest edge habitats, so is likely to benefit from small-scale forest clearing, e.g. that induced by selective logging. However, two of its known sites are very close to the Tchimbélé dam, the construction of which has presumably affected the extent and quality of habitat and number of individuals. The six subpopulations represent six locations in the sense of IUCN (2012), and the species qualifies as “Vulnerable” [VU B2ab(iii,v)] using the IUCN Red List Categories and Criteria (IUCN, 2012). Notes. – The earliest collection of this species, J.J.F.E. de Wilde et al. 284, was cited as Pseudosabicea proselyta by SOSEF et al. (2006). Sabicea dichrosepala is indeed closely related to S. proselyta (the two share, in particular, a similar seed ornamentation) but differs by the characters mentioned in Table 1, the most conspicuous of which are the bicoloured calyx, and the inflorescences that are very dense and glomeruliform in the flowering stage. It is not known whether the species is heterostylous; the only open flowers seen (Fig. 6D) are short-styled. Paratypi. – GABON. Estuaire: Mts de Cristal, vers le secteur Mont Séni, Concession BSG, 0°50'52"N 10°24'12"E, 8.III.2019, fl., Bidault et al. 4401 (BRLU, LBV n.v., MO); forest exploitation Leroy, 20 km NW of Asok, 27.I.1983, buds, J.J.F.E. de Wilde et al. 284 (BR, LBV, P, WAG); Mts de Cristal, Tchimbélé-Nkol Madouaka, 17.II.2007, fr., Leal et al. 1396 (BR). Ngounié: Mouyanama falls, at base of Mt Songou, 23.II.2008, buds, Dessein et al. 2111 (LBV); Massif du Chaillu au SE localité Moudouma, 21.IX.2001, imm.fr., Mayombo-Nzengue 928 (LBV). Woleu-Ntem: 2 km N of Tchimbélé on former road to Asok, 6.II.2008, old fl., Dessein et al. 1741 (BR, LBV)., Published as part of Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, pp. 115-143 in Candollea 75 (1) on pages 122-124, DOI: 10.15553/c2020v751a12, http://zenodo.org/record/5724782, {"references":["IUCN (2012). IUCN Red List Categories and Criteria, version 3.1. Ed. 2. IUCN Species Survival Commission, Gland & Cambridge.","SOSEF, M. S. M., J. J. WIERINGA, C. C. H. JONGKIND, G. ACHOUNDONG, Y. AZIZET ISSEMBE, D. BEDIGIAN, R. G. VAN DEN BERG, F. J. BRETELER, M. CHEEK, J. DEGREEF, R. B. FADEN, P. GOLDBLATT, L. J. G. VAN DER MAESEN, L. NGOK BANAK, R. NIANGADOUMA, T. NZABI, B. NZIENGUI, Z. S. ROGERS, T. STEVART, J. L. C. H. VAN VALKENBURG, G. WALTERS & J. J. F. E. DE WILDE (2006). Checklist des plantes vasculaires du Gabon. Checklist of Gabonese vascular plants. Scripta Bot. Belg. 35."]}

Precise accounting of carbon stocks and fluxes in tropical vegetation using remote sensing approaches remains a challenging exercise, as both signal saturation and ground sampling limitations contribute to inaccurate extrapolations. Airborne LiDAR Scanning (ALS) data can be used as an intermediate level to radically increase sampling and enhance model calibration. Here we tested the potential of using ALS data for upscaling vegetation aboveground biomass (AGB) from field plots to a forest-savanna transitional landscape in the Guineo–Congolian region in Cameroon, using either a design-based approach or a model-based approach leveraging multispectral satellite imagery. Two sets of reference data were used: (1) AGB values collected from 62 0.16-ha plots distributed both in forests and savannas; and (2) an AGB map generated form ALS data. In the model-based approach, we trained Random Forest models using predictors from recent sensors of varying spectral and spatial resolutions (Spot 6/7, Landsat 8, and Sentinel 2), along with biophysical predictors derived after pre-processing into the Overland processing chain, following a forward variable selection procedure with a spatial 4-folds cross validation. The models calibrated with field plots lead to a systematic overestimation in AGB density estimates and a root mean squared prediction error (RMSPE) of up to 65 Mg.ha−1 (90%), whereas calibration with ALS lead to low bias and a drop of ~30% in RMSPE (down to 43 Mg.ha−1, 58%) with little effect of the satellite sensor used. Decomposing bias along the AGB density range, we show that multispectral images can (in some specific cases) be used for unbiased prediction at landscape scale on the basis of ALS-calibrated statistical models. However, our results also confirm that, whatever the spectral indices used and attention paid to sensor quality and pre-processing, the signal is not sufficient to warrant accurate pixelwise predictions, because of large relative RMSPE, especially above (200–250 t/ha). The design-based approach, for which average AGB density values were attributed to mapped land cover classes, proved to be a simple and reliable alternative (for landscape to region level estimations), when trained with dense ALS samples.

International audience; Determining where species diversify (cradles) and persist (museums) over evolutionary time is fundamental to understanding the distribution of biodiversity and for conservation prioriti-zation. Here, we identify cradles and museums of angiosperm generic diversity across tropical Africa, one of the most biodiverse regions on Earth. Regions containing nonrandom concentrations of young (neo-) and old (paleo-) endemic taxa were identified using distribution data of 1719 genera combined with a newly generated time-calibrated mega-phylogenetic tree. We then compared the identified regions with the current network of African protected areas (PAs). At the generic level, phylogenetic diversity and endemism are mainly concentrated in the biogeographically complex region of Eastern Africa. We show that mountainous areas are centres of both neo-and paleo-endemism. By contrast, the Guineo-Congolian lowland rain forest region is characterized by widespread and old lineages. We found that the overlap between centres of phylogenetic endemism and PAs is high (> 85%). We show the vital role played by mountains acting simultaneously as cradles and museums of tropical African plant biodiversity. By contrast, lowland rainforests act mainly as museums for generic diversity. Our study shows that incorporating large-scale taxonomically verified distribution datasets and mega-phylogenies lead to an improved understanding of tropical plant biodiversity evolution.