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It is time to synthesize the knowledge that has been generated through more than 260 years of botanical exploration, taxonomic and, more recently, phylogenetic research throughout the world. The adoption of an updated Global Strategy for Plant Conservation (GSPC) in 2011 provided the essential impetus for the development of the World Flora Online (WFO) project. The project represents an international, coordinated effort by the botanical community to achieve GSPC Target 1, an electronic Flora of all plants. It will be a first‐ever unique and authoritative global source of information on the world's plant diversity, compiled, curated, moderated and updated by an expert and specialist‐based community (Taxonomic Expert Networks – “TENs” – covering a taxonomic group such as family or order) and actively managed by those who have compiled and contributed the data it includes. Full credit and acknowledgement will be given to the original sources, allowing users to refer back to the primary data. A strength of the project is that it is led and endorsed by a global consortium of more than 40 leading botanical institutions worldwide. A first milestone for producing the World Flora Online is to be accomplished by the end of 2020, but the WFO Consortium is committed to continuing the WFO programme beyond 2020 when it will develop its full impact as the authoritative source of information on the world's plant biodiversity.

Background and aims – Rubieae is a tribe in the subfamily Rubioideae characterised by herbaceous plants with verticillate leaves and flowers with a rudimentary or absent calyx and a short, cup-shaped corolla. This is in contrast to the flowers of most other Rubiaceae, in which the tubular corolla is longer than the corolla lobes. Also, the description by Payer, a French 19th century pioneer of floral ontogenetic research, of the floral development in Asperula, Galium, and Rubia deviates from recent insights about the development of tubular corollas, which are based on investigations of flowers of tropical Rubiaceae. Tubular corollas are currently considered as resulting from the development of underlying annular intercalary meristems, whereas Payer explained the tubular corollas in the three taxa by postgenital fusion. We therefore tested both hypotheses in six Rubieae genera, including the three taxa studied by Payer.Methods – Floral ontogeny of ten species in six Rubieae genera based on scanning electron (SEM) and light microscopy (LM). Conclusions – Our results suggest that, in all species studied, the mature phenotype of the corolla as well as the epipetaly of the stamens is caused by a combination of three developmental processes (the development of a stamen-corolla tube, the development of a corolla tube sensu stricto, and postgenital fusion), and the relative moment of activation of each of these processes during floral development (plastochron variation or heterochrony).

Background and Aims Floral diversity as a result of plant–pollinator interactions can evolve by two distinct processes: shifts between pollination systems or divergent use of the same pollinator. Although both are pollinator driven, the mode, relative importance and interdependence of these different processes are rarely studied simultaneously. Here we apply a phylogenetic approach using the Balsaminaceae (including the species-rich genus Impatiens) to simultaneously quantify shifts in pollination syndromes (as inferred from the shape and colour of the perianth), as well as divergent use of the same pollinator (inferred from corolla symmetry). Methods For 282 species we coded pollination syndromes based on associations between floral traits and known pollination systems, and assessed corolla symmetry. The evolution of these traits was reconstructed using parsimony- and model-based approaches, using phylogenetic trees derived from phylogenetic analyses of nuclear ribosomal and plastid DNA sequence data. Key Results A total of 71 % of studied species have a bee pollination syndrome, 22 % a bimodal syndrome (Lepidoptera and bees), 3 % a bird pollination syndrome and 5 % a syndrome of autogamy, while 19 % of species have an asymmetrical corolla. Although floral symmetry and pollination syndromes are both evolutionarily labile, the latter shifts more frequently. Shifts in floral symmetry occurred mainly in the direction towards asymmetry, but there was considerable uncertainty in the pattern of shift direction for pollination syndrome. Shifts towards asymmetrical flowers were associated with a bee pollination syndrome. Conclusion Floral evolution in Impatiens has occurred through both pollination syndrome shifts and divergent use of the same pollinator. Although the former appears more frequent, the latter is likely to be underestimated. Shifts in floral symmetry and pollination syndromes depend on each other but also partly on the region in which these shifts take place, suggesting that the occurrence of pollinator-driven evolution may be determined by the availability of pollinator species at large geographical scales.

Background Variation in shape and size of many floral organs is related to pollinators. Evolution of such organs is driven by duplication and modification of MADS-box and MYB transcription factors. We applied a combination of micro-morphological (SEM and micro 3D-CT scanning) and molecular techniques (transcriptome and RT-PCR analysis) to understand the evolution and development of the callus, stelidia and mentum, three highly specialized floral structures of orchids involved in pollination. Early stage and mature tissues were collected from flowers of the bee-pollinated Phalaenopsis equestris and Phalaenopsis pulcherrima, two species that differ in floral morphology: P. equestris has a large callus but short stelidia and no mentum, whereas P. pulcherrima has a small callus, but long stelidia and a pronounced mentum. Results Our results show the stelidia develop from early primordial stages, whereas the callus and mentum develop later. In combination, the micro 3D-CT scan analysis and gene expression analyses show that the callus is of mixed petaloid-staminodial origin, the stelidia of staminodial origin, and the mentum of mixed sepaloid-petaloid-staminodial origin. SEP clade 1 copies are expressed in the larger callus of P. equestris, whereas AP3 clade 1 and AGL6 clade 1 copies are expressed in the pronounced mentum and long stelidia of P. pulcherrima. AP3 clade 4, PI-, AGL6 clade 2 and PCF clade 1 copies might have a balancing role in callus and gynostemium development. There appears to be a trade-off between DIV clade 2 expression with SEP clade 1 expression in the callus, on the one hand, and with AP3 clade 1 and AGL6 clade 1 expression in the stelidia and mentum on the other. Conclusions We detected differential growth and expression of MADS box AP3/PI-like, AGL6-like and SEP-like, and MYB DIV-like gene copies in the callus, stelidia and mentum of two species of Phalaenopsis, of which these floral structures are very differently shaped and sized. Our study provides a first glimpse of the evolutionary developmental mechanisms driving adaptation of Phalaenopsis flowers to different pollinators by providing combined micro-morphological and molecular evidence for a possible sepaloid–petaloid–staminodial origin of the orchid mentum.

Phalaenopsis is an important ornamental pot plant for the global horticultural market. The inflorescences of Phalaenopsis horticultural hybrids require support from a stick during plant cultivation because of the weight of multiple large flowers. Developing a horticultural hybrid with a sufficiently lignified inflorescence stem that does not require additional support could be a way to reduce the costs of production. This study aimed to (i) determine the orientation and degree of lignification in the inflorescence stem of different species and horticultural hybrids of Phalaenopsis and investigate whether these lignification patterns follow any (ii) topological or (iii) phylogenetic pattern of interest to further explore in genetic precision breeding. Inflorescences of comparable devel- opmental stages of six species and 17 horticultural hybrids of flowering Phalaenopsis orchids were sampled. The orientation of the inflorescence varied from erect, sub-erect, arching, to pendant. The degree of lignification was measured with ImageJ using stained microscopic tissue sections and statistically analyzed. A molecular phylogeny of the species of Phalaenopsis was reconstructed based on plastid and nuclear ribosomal DNA sequences to analyze phylogenetic patterns. Our results show a significant difference in the degree of lignification between the different Phalaenopsis species and hybrids, between peduncle and rachis, and among the six different inflorescence positions analyzed. We found a positive correlation between inflorescence orientation and the proportion of lignified area per total stem area and the proportional thickness of the lignified fiber walls in the peduncle. We conclude that the degree of lignification is heritable, as we observed among our sample size a higher positive correlation between stem lignification variables among closely related taxa compared to more distantly related ones. However, a larger species sampling is needed to further validate our results.

The systematic significance of wood anatomical characters within Ericales is evaluated using separate and combined parsimony analyses including 23 wood characters and 3945 informative molecular characters. Analyses of wood features alone result in poorly resolved and conflicting topologies. However, when pedomorphic character states are coded as inapplicable, the combined bootstrap topology results in an increase of resolution and support at most deeper nodes compared with the molecular analyses. This suggests that phylogenetic information from the limited number of morphological characters is not completely swamped by an overwhelming amount of molecular data. Based on the morphology of vessels and fibers, and the distribution of axial parenchyma, two major wood types can be distinguished within Ericales: (i) a "primitive" type, nearly identical to the wood structure in the more basal outgroup Cornales, which is likely to have persisted in one major clade, and (ii) a "derived" type that must have evolved in at least two separate evolutionary lines. The occurrence of the first type is strongly correlated with shrubs to small trees growing in cold temperate or tropical montane regions, while the second type is common in tall trees of tropical lowlands. This favors the inclusion of ecologically adaptive features in phylogeny reconstruction. (c) The Willi Hennig Society 2006. ispartof: Cladistics vol:23 issue:3 pages:229-254 ispartof: location:United States status: published

Due to morphological reduction and absence of amplifiable plastid genes, the identification of photosynthetic relatives of heterotrophic plants is problematic. Although nuclear and mitochondrial gene sequences may offer a welcome alternative source of phylogenetic markers, the presence of rate heterogeneity in these genes may introduce bias/systematic error in phylogenetic analyses. We examine the phylogenetic position of Thismiaceae based on nuclear 18S rDNA and mitochondrial atpA DNA sequence data, as well as using parsimony, likelihood and Bayesian inference methods. Significant differences in evolutionary rates of these genes between closely related taxa lead to conflicting results: while parsimony analyses of 18S rDNA and combined data strongly support the monophyly of Thismiaceae, Bayesian inference, with and without a relaxed molecular clock, as well as the Swofford-Olsen-Waddell-Hillis (SOWH) test confidently reject this hypothesis. We show that rate heterogeneity in our data leads to long-branch attraction artifacts in parsimony analysis. However, using model-based inference methods the question of whether Thismiaceae are monophyletic remains elusive. On the one hand maximum likelihood nonparametric bootstrapping and parametric hypothesis tests fail to support a paraphyletic Thismiaceae, on the other hand Bayesian inference methods (both without and with a relaxed clock) significantly reject a monophyletic Thismiaceae. These results show that an adequate sampling, the use of rate homogeneous data, and the application of different inference methods are important factors for developing phylogenetic hypotheses of myco-heterotrophic plants. (C) The Willi Hennig Society 2009. ispartof: Cladistics vol:25 issue:1 pages:64-77 ispartof: location:United States status: published

The dry one-seeded fruits (cypselae) of the Asteraceae are often crowned with a pappus, an appendage of hairs or scales that assists in dispersal. It is generally assumed, but little investigated, that the pappus represents the outer floral whorl where the sepals are usually located. We analysed pappus-sepal homology in dandelions using micromorphological and floral gene expression analyses. We show that the pappus initiates from a ring primordium at the base of the corolla, heterochronic to the petals. Pappus parts form from this ring, with those in the alternipetalaous position usually being ahead in growth, referring to sepal identity. Tof-APETALLA1 expression increased during floret development and was highest in mature pappus. Tof-PISTILLATA expression was high and confined to the floral tissues containing the petals and stamens, consistent with expectations for sepals. Apart from the pappus, the dispersal structure of dandelion consists of the upper part of the fruit, the beak, which originates from the inner floral whorl. Thus, our results support the homology of the pappus with the sepals, but show that it is highly derived. Together with our floral stage definitions and verified qPCR reference genes, they provide a basis for evolution and development studies in dandelions and possibly other Asteraceae. ispartof: PLANTS-BASEL vol:10 issue:8 ispartof: location:Switzerland status: published

Background and Aims The ability to avoid drought-induced embolisms in the xylem is one of the essential traits for plants to survive periods of water shortage. Over the past three decades, hydraulic studies have been focusing on trees, which limits our ability to understand how herbs tolerate drought. Here we investigate the embolism resistance in inflorescence stems of four Arabidopsis thaliana accessions that differ in growth form and drought response. We assess functional traits underlying the variation in embolism resistance amongst the accessions studied using detailed anatomical observations. Methods Vulnerability to xylem embolism was evaluated via vulnerability curves using the centrifuge technique and linked with detailed anatomical observations in stems using light microscopy and transmission electron microscopy. Key Results The data show significant differences in stem P50, varying 2-fold from −1.58 MPa in the Cape Verde Island accession to −3.07 MPa in the woody soc1 ful double mutant. Out of all the anatomical traits measured, intervessel pit membrane thickness (TPM) best explains the differences in P50, as well as P12 and P88. The association between embolism resistance and TPM can be functionally explained by the air-seeding hypothesis. There is no evidence that the correlation between increased woodiness and increased embolism resistance is directly related to functional aspects. However, we found that increased woodiness is strongly linked to other lignification characters, explaining why mechanical stem reinforcement is indirectly related to increased embolism resistance. Conclusions The woodier or more lignified accessions are more resistant to embolism than the herbaceous accessions, confirming the link between increased stem lignification and increased embolism resistance, as also observed in other lineages. Intervessel pit membrane thickness and, to a lesser extent, theoretical vessel implosion resistance and vessel wall thickness are the missing functional links between stem lignification and embolism resistance.

Necklace orchids (Coelogyninae, Epidendroideae) have been used in traditional medicine practices for centuries. Previous studies on a subset of unrelated orchid species utilized in these traditional practices revealed they possessed antimicrobial, anti-inflammatory, and antioxidant activity, providing experimental proof for their medicinal properties. To date however none of these species have been investigated ethno-botanically in a phylogenetic context. This study carried out comparative bioprospecting for a group of wild orchids using EBDCS (the Economic Botany Data Collection Standards) organ targeted and biological response methods. The traditional medicinal use of necklace orchids was recorded from books and journals published between 1984 and 2016. Two orchids, Coelogyne cristata and Coelogyne fimbriata, were selected, cultivated both indoors and outdoors, and the antimicrobial properties on extracts from their leaves and pseudobulbs tested against a selection of human pathogens. A molecular phylogeny of Coelogyninae based on nuclear ribosomal ITS and plastid matK DNA sequences obtained from 148 species was reconstructed with Maximum Likelihood (ML) using RAxML, Maximum Parsimony (MP) using PAUP and Bayesian Inference using MrBayes. Bioprospecting comparison of EBDCS and biological response was carried out using customized R scripts. Ethanolic extracts obtained from leaves of C. fimbriata inhibited growth of Bacillus cereus, Staphylococcus aureus, and Yersinia enterocolitica, confirming the antimicrobial properties of these extracts. Leaf extracts were found to have slightly stronger antimicrobial properties for plants cultivated outdoors than indoors. These differences were not found to be statistically significant though. Three hot nodes with high potency for antimicrobial activities were detected with the EBDCS organ targeted classification method, and eight hot nodes were detected with the biological response classification method. The biological response classification method is thus a more effective tool in finding hot nodes amongst clades of species with high medicinal potential. Indonesia Endowment Fund for Education/[0044737/SC/D/2/lpdp2014]/LPDP/Indonesia Naturalis Biodiversity Center/[]//Países Bajos Centro Nacional de Alta Tecnología/[]/CeNAT/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

An enigmatic feature of tropical pitcher plants belonging to the genus Nepenthes is their dimorphic prey-capturing pitfall traps. In many species, the conspicuously shaped upper and lower pitchers grow from a swollen leaf tendril tip until finally opening as insect-alluring devices. Few have studied the ontogeny of these traps from an anatomical and quantitative morphological perspective. We investigated whether the anatomy and development of lower and upper type pitchers of N. rafflesiana differ or overlap in terms of 3D geometric morphology and microstructure progression and presence. We hypothesized that there is an overlap in the initial, but not all, developmental stages of the two pitcher types and that one pitcher type is suspended in development. We identified four important morphological changes of pitcher ontogeny and defined these as curvation, elongation, inflation and maturation phases. Pitcher length indicated progress through developmental phases, and we propose to use it as a tool for indication of developmental stage. Microstructure development coincided with the developmental phases defined. Additionally, we discovered a new anatomical feature of extrafloral nectariferous peristomal glands between the inner peristome ridges of upper and lower pitchers being hollow and analyze the chemistry of the sugars on the outside of these glands. Ontogenetic shape analysis indicated that upper and lower pitcher types develop with similar phase progression but have no directly overlapping morphology. This means that upper pitchers are not a derived state from lower pitchers. Independent developmental programs evolved to produce distinctly shaped upper and lower pitchers in Nepenthes, likely to exploit different food sources. ispartof: PLANTS-BASEL vol:9 issue:11 ispartof: location:Switzerland status: published

Pleurothallidinae (Epidendreae) are a megadiverse Neotropical orchid subtribe comprising > 5100 species, most of which are probably pollinated by Diptera. The role of pollinators as drivers of species diversity is largely unknown because knowledge of pollination systems in Pleurothallidinae is still scarce. Here, we addressed the pollination of Trichosalpinx s.s. through study of floral anatomy, pollinator behaviour and floral traits shared with other angiosperms to elucidate its pollination mechanisms. We identified midge specimens with DNA barcoding and morphology, documented pollination with video recordings, studied the anatomy of flowers by combining microscopy (light microscopy, scanning electron microscopy and transmission electron microscopy) and histochemistry and analysed floral scents with gas chromatography–mass spectrometry. We found that two Trichosalpinx spp. are pollinated exclusively by female biting midges of a Forcipomyia (Euprojoannisia) sp. (Ceratopogonidae). The midges land on the motile lip and appear to suck substances from its papillose surface. We detected secretion of carbohydrates and proteins on the lip and sepals, and thus, Trichosalpinx might stimulate a protein collection instinct in female biting midges. The well-developed mandibles and poorly developed laciniae of the pollinators indicate that they mainly feed on invertebrate hosts from which they draw haemolymph. Thus, Trichosalpinx flowers offer small quantities of proteins and carbohydrates that may act as flavour teases and together with the colour, fragrances, trichomes and movement of the lip, they probably form part of a complex deceptive system. Some other angiosperms that are also pollinated by biting midges possess similar dark purple flowers with ciliate ornamentation and use myophily, sapromyophily or kleptomyiophily as strategies to exploit different families of Diptera as pollinators. One Forcipomyia sp. (Euprojoannisia) is kleptoparasitic, suggesting that kleptomyiophily may have evolved in Trichosalpinx. The similar floral morphology among members of Trichosalpinx and some species of the closely related genera Anathallis and Lankesteriana suggests that they are also pollinated by biting midges. Sistema Nacional de Áreas de Conservación/[026-2011-SINAC]/SINAC/Costa Rica Sistema Nacional de Áreas de Conservación/[073-2012-SINAC]/SINAC/Costa Rica Sistema Nacional de Áreas de Conservación/[R-SINAC-DE-077]/SINAC/Costa Rica Sistema Nacional de Áreas de Conservación/[SINAC-SEGASP-PI-R-019-2015]/SINAC/Costa Rica Leiden University/[]//Países Bajos Universidad de Costa Rica/[814-B6-140]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

Tropical forests represent vast carbon stocks and continue to be key carbon sinks and buffer climate changes. The international policy constructed several mechanisms aiming at conservation and sustainable use of these forests. Illegal logging is an important threat of forests, especially in the tropics. Several laws and regulations have been set up to combat illegal timber trade. Despite significant enforcement efforts of these regulations, illegal logging continues to be a serious problem and impacts for the functioning of the forest ecosystem and global biodiversity in the tropics. Microscopic analysis of wood samples and the use of conventional plant DNA barcodes often do not allow to distinguish closely-related species. The use of novel molecular technologies could make an important contribution for the identification of tree species. In this study, we used high-throughput sequencing technologies and bioinformatics tools to obtain the complete de-novo chloroplast genome of 62 commercial African timber species using the genome skimming method. Then, we performed a comparative genomic analysis that revealed new candidate genetic regions for the discrimination of closely-related species. We concluded that genome skimming is a promising method for the development of plant genetic markers to combat illegal logging activities supporting CITES, FLEGT and the EU Timber Regulation., info:eu-repo/semantics/published

The molecular clock hypothesis is an important concept in biology. Deviations from a constant rate of nucleotide substitution have been found widely among lineages, genomes, genes and individual sites. Phylogenetic research can accommodate for these differences in applying specific models of evolution. Lineage-specific rate heterogeneity however can generate bi- or multimodal distributions of substitution rates across the branches of a tree and this may mislead phylogenetic inferences with currently available models. The plant family Annonaceae is an excellent case to study lineage-specific rate heterogeneity. The two major sister subfamilies, Annonoideae and Malmeoideae, have shown great discrepancies in branch lengths. We used high-throughput sequencing data of 72 genes, 99 spacers and 16 introns from 24 chloroplast genomes and nuclear ribosomal DNA of 23 species to study the molecular rate of evolution in Annonaceae. In all analyses, longer branch lengths and/or higher substitution rates were found for the Annonoideae compared to the Malmeoideae. The Annonaceae had wide variability in chloroplast length, ranging from minimal 175,684 by to 201,723 for Annonoideae and minimal 152,357 to 170,985 bp in Malmeoideae, mostly reflecting variation in inverted-repeat length. The Annonoideae showed a higher GC-content in the conserved parts of the chloroplast genome and higher omega (dN/c/s)-ratios than the Malmeoideae, which could indicate less stringent purifying selection, a pattern that has been found in groups with small population sizes. This study generates new insights into the processes causing lineage-specific rate heterogeneity, which could lead to improved phylogenetic methods. (C) 2017 Elsevier Inc. All rights reserved.

Taxonomic delimitations are challenging because of the convergent and variable nature of phenotypic traits. This is evident in species-rich lineages, where the ancestral and derived states and their gains and losses are difficult to assess. Phylogenetic comparative methods help to evaluate the convergent evolution of a given morphological character, thus enabling the discovery of traits useful for classifications. In this study, we investigate the evolution of selected traits to test for their suitability for generic delimitations in the clade Lepanthes, one of the Neotropical species-richest groups. We evaluated every generic name proposed in the Lepanthes clade producing densely sampled phylogenies with Maximum Parsimony, Maximum Likelihood, and Bayesian approaches. Using Ancestral State Reconstructions, we then assessed 18 phenotypic characters that have been traditionally employed to diagnose genera. We propose the recognition of 14 genera based on solid morphological delimitations. Among the characters assessed, we identified 16 plesiomorphies, 12 homoplastic characters, and seven synapomorphies, the latter of which are reproductive features mostly related to the pollination by pseudocopulation and possibly correlated with rapid diversifications in Lepanthes. Furthermore, the ancestral states of some reproductive characters suggest that these traits are associated with pollination mechanisms alike promoting homoplasy. Our methodological approach enables the discovery of useful traits for generic delimitations in the Lepanthes clade and offers various other testable hypotheses on trait evolution for future research on Pleurothallidinae orchids because the phenotypic variation of some characters evaluated here also occurs in other diverse genera. Ministerio de Ambiente y Energía/[]/MINAE/Costa Rica Sistema Nacional de Áreas de Conservación/[]/SINAC/Costa Rica Universidad de Costa Rica/[814-B6-140]/UCR/Costa Rica Leiden University/[]//Países Bajos Royal Botanic Gardens, Kew/[]//Inglaterra UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

Understanding the evolution of biodiversity on Earth is a central aim in biology. Currently, various disciplines of science contribute to unravel evolution at all levels of life, from individual organisms to species and higher ranks, using different approaches and specific terminologies. The search for common origin, traditionally called homology, is a connecting paradigm of all studies related to evolution. However, it is not always sufficiently taken into account that defining homology depends on the hierarchical level studied (organism, population, and species), which can cause confusion. Therefore, we propose a framework to define homologies making use of existing terms, which refer to homology in different fields, but restricting them to an unambiguous meaning and a particular hierarchical level. We propose to use the overarching term "homology" only when "morphological homology," "vertical gene transfer," and "phylogenetic homology" are confirmed. Consequently, neither phylogenetic nor morphological homology is equal to homology. This article is intended for readers with different research backgrounds. We challenge their traditional approaches, inviting them to consider the proposed framework and offering them a new perspective for their own research. ispartof: SYSTEMATIC BIOLOGY vol:68 issue:5 pages:767-780 ispartof: location:England status: published

The pollen morphology of 63 African Impatiens species (Balsaminaceae) is studied using scanning electron microscopy. In addition, the pollen wall structure of five African Impatiens species was investigated with transmission electron microscopy. Pollen of African balsams is medium to large in size. Oblate Impatiens pollen is most common yet peroblate and suboblate pollen are also well represented. African pollen of the genus Impatiens is mainly circular, rectangular or elliptic. Reticulate sexine ornamentation is characteristic for most of the species investigated. Both homobrochate and heterobrochate pollen is present within the genus. Occasionally, the lumina are not entirely demarcated by muri, resulting in coalescence between adjacent lumina. The muri vary from slender with a tapering top edge, to slender with a rounded edge, to broad, more or less flattened muri. The tectal muri are always supported by two or three rows of short and massive columellae. Orbicules are absent in all species investigated. Observations of the pollen wall stratification show that pollen of African Impatiens consists of a thin foot layer, a lamellated endexine (characterized by remnants of the white lines) and a one-layered intine. Foot layer and endexine are slightly intermingled and therefore sometimes difficult to distinguish from each other.

Background and AimsPlant survival under extreme drought events has been associated with xylem vulnerability to embolism (the disruption of water transport due to air bubbles in conduits). Despite the ecological and economic importance of herbaceous species, studies focusing on hydraulic failure in herbs remain scarce. Here, we assess the vulnerability to embolism and anatomical adaptations in stems of seven herbaceous Brassicaceae species occurring in different vegetation zones of the island of Tenerife, Canary Islands, and merged them with a similar hydraulic–anatomical data set for herbaceous Asteraceae from Tenerife.MethodsMeasurements of vulnerability to xylem embolism using the in situ flow centrifuge technique along with light and transmission electron microscope observations were performed in stems of the herbaceous species. We also assessed the link between embolism resistance vs. mean annual precipitation and anatomical stem characters.Key ResultsThe herbaceous species show a 2-fold variation in stem P50 from –2.1 MPa to –4.9 MPa. Within Hirschfeldia incana and Sisymbrium orientale, there is also a significant stem P50 difference between populations growing in contrasting environments. Variation in stem P50 is mainly explained by mean annual precipitation as well as by the variation in the degree of woodiness (calculated as the proportion of lignified area per total stem area) and to a lesser extent by the thickness of intervessel pit membranes. Moreover, mean annual precipitation explains the total variance in embolism resistance and stem anatomical traits.ConclusionsThe degree of woodiness and thickness of intervessel pit membranes are good predictors of embolism resistance in the herbaceous Brassicaceae and Asteraceae species studied. Differences in mean annual precipitation across the sampling sites affect embolism resistance and stem anatomical characters, both being important characters determining survival and distribution of the herbaceous eudicots.

Phylogenetic relationships in species complexes and lineages derived from rapid diversifications are often challenging to resolve using morphology or standard DNA barcoding markers. The hyper-diverse genus Lepanthes from Neotropical cloud forest includes over 1200 species and many recent, explosive diversifications that have resulted in poorly supported nodes and morphological convergence across clades. Here, we assess the performance of 446 nuclear-plastid-mitochondrial markers derived from an anchored hybrid enrichment approach (AHE) coupled with coalescence- and species network-based inferences to resolve phylogenetic relationships and improve species recognition in the Lepanthes horrida species group. In addition to using orchid-specific probes to increase enrichment efficiency, we improved gene tree resolution by extending standard angiosperm targets into adjacent exons. We found high topological discordance among individual gene trees, suggesting that hybridization/polyploidy may have promoted speciation in the lineage via formation of new hybrid taxa. In addition, we identified ten loci with the highest phylogenetic informativeness values from these genomes. Most previous phylogenetic sampling in the Pleurothallidinae relies on two regions (ITS and matK), therefore, the evaluation of other markers such as those shown here may be useful in future phylogenetic studies in the orchid family. Coalescent-based species tree estimation methods resolved the phylogenetic relationships of the L. horrida species group. The resolution of the phylogenetic estimations was improved with the inclusion of extended anchor targets. This approach produced longer loci with higher discriminative power. These analyses also disclosed two undescribed species, L. amicitiae and L. genetoapophantica, formally described here, which are also supported by morphology. Our study demonstrates the utility of combined genomic evidence to disentangle phylogenetic relationships at very shallow levels of the tree of life, and in clades showing convergent trait evolution. With a fully resolved phylogeny, is it possible to disentangle traits evolving in parallel or convergently across these orchid lineages such as flower color and size from diagnostic traits such as the shape and orientation of the lobes of the petals and lip. ispartof: MOLECULAR PHYLOGENETICS AND EVOLUTION vol:129 pages:27-47 ispartof: location:United States status: published

Background and aims – A recent field expedition in the Campo-Ma'an/Akom II region in Cameroon resulted in the collection of a previously unknown Impatiens species, which resembles Impatiens macroptera and Impatiens pseudomacroptera. This study aims to describe and infer the evolutionary history of this novelty by using phylogenetics, biogeographic inference and dating estimation analyses. Methods – The new species was subject to a palynological, molecular phylogenetic and biogeographical analysis. In addition, a thorough morphological comparison with its closely related species was conducted. Key results – Morphological comparison and molecular phylogenetics corroborate its status as a new species, which is given the name Impatiens akomensis . Molecular data, based on ImpDEF1, ImpDEF2 and ITS indicate that Impatiens akomensis is most closely related to the Cameroonian I. macroptera, whereas the lineage towards I. macroptera and the novelty is sister to the Gabonese I. pseudomacroptera . Impatiens akomensis differs from I. macroptera and I. pseudomacroptera in having very strongly asymmetric white flowers, much thicker leaves, a narrowly elliptic leaf shape and a serrulate leaf margin, smaller lateral united petals (23.1–24.2 mm) and larger bracts (12–20 mm). The new species qualifies for endangered status under IUCN criteria B2 and probably B1. Conclusions – Dating analyses in combination with biogeographic inference, and ecological and environmental interpretation of the novelty and its closely related species allows us to infer the putative evolutionary history of Impatiens akomensis .

Background and aims The bacterial leaf nodule symbiosis is a close interaction between endophytes and their plant hosts, mainly within the coffee family. The interaction between Rubiaceae species and Burkholderia bacteria is unique due to its obligate nature, high specificity, and predominantly vertical transmission of the endophytes to the next generation of host plants. This vertical transmission is intriguing since it is the basis for the uniqueness of the symbiosis. However, unequivocal evidence of the location of the endophytes in the seeds is lacking. The aim of this paper is therefore to demonstrate the presence of the host specific endophyte in the seeds of Psychotria punctata and confirm its precise location. In addition, the suggested location of the endophyte in other parts of the host plant is investigated. Methods To identify and locate the endophyte in Psychotria punctata, a two-level approach was adopted using both a molecular screening method and fluorescent in situ hybridisation microscopy. Key results The endophytes, molecularly identified as Candidatus Burkholderia kirkii, were detected in the leaves, vegetative and flower buds, anthers, gynoecium, embryos, and young twigs. In addition, they were in situ localised in leaves, flowers and shoot apical meristems, and, for the first time, in between the cotyledons of the embryos. Conclusions Both independent techniques detected the host specific endophyte in close proximity to the shoot apical meristem of the embryo, which confirms for the first time the exact location of the endophytes in the seeds. This study provides reliable proof that the endophytes are maintained throughout the growth and development of the host plant and are transmitted vertically to the offspring.

Three new species of Impatiens (Balsaminaceae) from Myanmar are here described: I. decurva Ruchis. & S.B. Janssens, I. hartnolliae Hook. f. ex Ruchis. & Suksathan, and I. oblongata Ruchis. &Van der Niet. The 5-lobed short fusiform fruit of all three species suggests that they are members of subgen. Impatiens sect. Uniflorae Hook. f. & Thomson. For I. decurva and I. oblongata, subgenus membership was corroborated by phylogenetic analyses of a combined dataset of nuclear ITS and plastid atpB-rbcL intergenic spacer DNA sequences. This was not possible for I. hartnolliae, which is only known from a single herbarium specimen.

A revision of the Balsaminaceae of Myanmar is presented based on herbarium collections and a field trip in 2015. Sixty-five species, unevenly distributed across one monotypic (Hydrocera) and one species-rich genus (Impatiens), are recognised. An identification key to species is presented. Twenty species are new records for the country, 17 names are typified and seven species names are synonymized. For each species, a description of the morphology, phenology, ecology and distribution range is provided.

© 2018 The Authors. Functional Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society. Insular woodiness refers to the evolutionary transition from herbaceousness towards derived woodiness on (sub)tropical islands and leads to island floras that have a higher proportion of woody species compared to floras of nearby continents. Several hypotheses have tried to explain insular woodiness since Darwin's original observations, but experimental evidence why plants became woody on islands is scarce at best. Here, we combine experimental measurements of hydraulic failure in stems (as a proxy for drought stress resistance) with stem anatomical observations in the daisy lineage (Asteraceae), including insular woody Argyranthemum species from the Canary Islands and their herbaceous continental relatives. Our results show that stems of insular woody daisies are more resistant to drought-induced hydraulic failure than the stems of their herbaceous counterparts. The anatomical character that best predicts variation in embolism resistance is intervessel pit membrane thickness (T PM ), which can be functionally linked with air bubble dynamics throughout the 3D vessel network. There is also a strong link between T PM vs. degree of woodiness and thickness of the xylem fibre wall vs. embolism resistance, resulting in an indirect link between lignification and resistance to embolism formation. Thicker intervessel pit membranes in Argyranthemum functionally explain why this insular woody genus is more embolism resistant to drought-induced failure compared to the herbaceous relatives from which it has evolved, but additional data are needed to confirm that palaeoclimatic drought conditions have triggered wood formation in this daisy lineage. A plain language summary is available for this article. ispartof: FUNCTIONAL ECOLOGY vol:32 issue:6 pages:1467-1478 status: published

Background and Aims Flowers of Geraniaceae and Hypseocharitaceae are generally considered as morphologically simple. However, previous studies indicated complex diversity in floral architecture including tendencies towards synorganization. Most of the species have nectar-rewarding flowers which makes the nectaries a key component of floral organization and architecture. Here, the development of the floral nectaries is studied and placed into the context of floral architecture. Methods Seven species from Geraniaceae and one from Hypseocharitaceae were investigated using scanning electron microscopy and light microscopy. Samples were prepared and processed using standard protocols. Key Results The development of the nectary glands follows the same trajectory in all species studied. Minor differences occur in the onset of nectarostomata development. The most striking finding is the discovery that a short anthophore develops via intercalary growth at the level of the nectary glands. This anthophore lifts up the entire flower apart from the nectary gland itself and thus plays an important role in floral architecture, especially in the flowers of Pelargonium. Here, the zygomorphic flowers show a particularly extensive receptacular growth, resulting in the formation of a spur-like receptacular cavity ('inner spur'). The nectary gland is hidden at the base of the cavity. Various forms of compartmentalization, culminating in the 'revolver flower' of Geranium maderense, are described. Conclusions Despite the superficial similarity of the flowers in Geraniaceae and Hypseocharitaceae, there is broad diversity in floral organization and floral architecture. While the receptacular origin of the spur-like cavity in Pelargonium had already been described, anthophore formation via intercalary growth of the receptacle in the other genera had not been previously documented. In the context of the most recent phylogenies of the families, an evolutionary series for the floral architecture is proposed, underscoring the importance of synorganization in these seemingly simple flowers.

Background and Aims The first documented observation of pollination in Pleurothallidinae was that of Endre ́s, who noticed that the ‘viscid sepals’ of Specklinia endotrachys were visited by a ‘small fly’. Chase would later iden- tify the visiting flies as being members of the genus Drosophila. This study documents and describes how species of the S. endotrachys complex are pollinated by different Drosophila species. Methods Specimens of Specklinia and Drosophila were collected in the field in Costa Rica and preserved in the JBL and L herbaria. Flies were photographed, filmed and observed for several days during a 2-year period and were identified by a combination of non-invasive DNA barcoding and anatomical surveys. Tissue samples of the sepals, petals and labellum of Specklinia species were observed and documented by SEM, LM and TEM. Electroantennogram experiments were carried out on Drosophila hydei using the known aggregation pheromones ethyl tiglate, methyl tiglate and isopropyl tiglate. Floral compounds were analysed by gas chromatography–mass spectometry using those same pheromones as standards. Key Results Flowers of S. endotrachys, S. pfavii, S. remotiflora and S. spectabilis are visited and pollinated by several different but closely related Drosophila species. The flies are arrested by aggregation pheromones, including ethyl tiglate, methyl tiglate and isopropyl tiglate, released by the flowers, and to which at least D. hydei is very sen- sitive. Visible nectar drops on the adaxial surface of sepals are secreted by nectar-secreting stomata, encouraging male and female Drosophila to linger on the flowers for several hours at a time. The flies frequently show courtship behaviour, occasionally copulating. Several different Drosophila species can be found on a single Specklinia species. Conclusions Species of the S. endotrachys group share a similar pollination syndrome. There seem to be no spe- cies-specific relationships between the orchids and the flies. It is not expected that Specklinia species will hybridize naturally as their populations do not overlap geographically. The combination of pheromone attraction and nectar feeding is likely to be a generalized pollination syndrome in Pleurothallidinae. Ministerio del Ambiente y Energía/[]/MINAE/Costa Rica Sistema Nacional de Áreas de Conservación/[]/SINAC/Costa Rica Universidad de Costa Rica/[814-B1-239]/UCR/Costa Rica Universidad de Costa Rica/[814-B3-075]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

Background and aims – In Rubiaceae, most flowers have a tubular corolla. Earlier studies showed that a tubular corolla may develop from an annular primordium or result from postgenital fusion of petals. Often stamen-corolla tubes are formed, concurring with epipetaly. Moreover, flowers with a fenestrated tubular corolla occur. The scattered distribution of species with corolla splits in Rubiaceae suggests a multiple origin. We intended to answer the following questions: (1) should the tubular corollas studied be assigned to a single or to several character states?; and (2) are the corolla splits studied homologous? We investigated the corolla development in five species of the Spermacoceae alliance with corolla splits in comparison with a Spermacoce species without. Methods – Floral developmental studies using scanning electron microscopy (SEM) and light microscopy (LM). Results – In Spermacoce, the tubular corolla with epipetalous stamens originates from an annular primordium. In Sacosperma and Pentas, the tubular corolla develops similarly with the stamens fixed basally. In Paederia and Pentodon, individual petal primordia originate on a ring wall. Next, stamen primordia appear adaxially on the ring wall. Then, the bases of the petals fuse partially, resulting in fenestrated tubular corollas. In Sacosperma and Pentas, corolla splits are actively formed in an initially closed tubular corolla. Conclusions – The tubular corollas of the species studied in Spermacoce, Sacosperma and Pentas are early sympetalous. Those in Paederia and Pentodon are late sympetalous. The tubular corolla results from a combination of three developmental processes: the formation of (1) a stamen-corolla tube, (2) a corolla tube sensu stricto, and (3) postgenital fusion of petals. The final form of the tubular corolla and the stamen insertion depend on the relative activity of these processes. Consequently, similar looking tubular corollas may constitute different character states. The corolla splits studied constitute two different cryptic character states in respectively Sacosperma / Pentas and Paederia/Pentodon .

Aim Many plant families have a disjunct distribution across the southern Pacific Ocean, including the mycoheterotrophic family Corsiaceae, which provides a prime example of this biogeographical pattern. A better grasp of the family's evolutionary relationships is needed to understand its historical biogeography. We therefore aimed to (1) test the uncertain monophyly of Corsiaceae, (2) define its phylogenetic position, and (3) estimate divergence times for the family, allowing us to assess whether the distribution of the family is the result of vicariance. Location Southern South America and Australasia. Methods We analysed various combinations of mitochondrial and nuclear data to address the monophyly, phylogenetic position and age of Corsiaceae. To test its monophyly, we used a three-locus data set including most monocot orders, and to infer its exact phylogenetic position, we used a five-locus extended data set. We corroborated these findings using an independent plastome dataset. We then used a two-locus dataset with taxa from all monocot orders, and a three-locus dataset containing only taxa of Liliales, to estimate divergence times using a fossil-calibrated uncorrelated lognormal relaxed-clock approach. Results Corsiaceae is a monophyletic family and the sister group of Campynemataceae. This clade is the sister group of all other Liliales. The crown age of Corsiaceae is estimated to be 53 Ma (95% confidence interval 30–76 Ma). Main conclusions Corsiaceae is an ancient family of mycoheterotrophic plants, whose crown age overlaps with the plate-tectonic split of Gondwana, consistent with a vicariance-based explanation for its current distribution.

© 2017, Museum National d'Histoire Naturelle. All rights reserved. Astiella is an herbaceous genus endemic to Madagascar, originally described with a single species A. delicatula Jovet. Molecular and morphological evidence place it in the tribe Spermacoceae s. lat. of Rubiaceae. During herbarium studies and fieldwork in Madagascar, 11 new Astiella species were identified and these are described here: A. antongilensis Groeninckx sp. nov., A. antsalovansis Groeninckx sp. nov., A. confusa Groeninckx sp. nov., A. deblockiae Groeninckx sp. nov., A. desseinii Groeninckx sp. nov., A. homolleae Groeninckx sp. nov., A. latifolia Groeninckx sp. nov., A. longifimbria Groeninckx sp. nov., A. perrieri Groeninckx sp. nov., A. pulla Groeninckx sp. nov., and A. tsaratanensis Groeninckx sp. nov. The genus Astiella now holds 12 species in total that are all endemic to Madagascar. ispartof: European Journal of Taxonomy vol:312 issue:312 pages:1-40 status: published

Genetic variation in the tomato clade was explored by sequencing a selection of 84 tomato accessions and related wild species representative for the Lycopersicon, Arcanum, Eriopersicon, and Neolycopersicon groups. We present a reconstruction of three new reference genomes in support of our comparative genome analyses. Sequence diversity in commercial breeding lines appears extremely low, indicating the dramatic genetic erosion of crop tomatoes. This is reflected by the SNP count in wild species which can exceed 10 million i.e. 20 fold higher than in crop accessions. Comparative sequence alignment reveals group, species, and accession specific polymorphisms, which explain characteristic fruit traits and growth habits in tomato accessions. Using gene models from the annotated Heinz reference genome, we observe a bias in dN/dS ratio in fruit and growth diversification genes compared to a random set of genes, which probably is the result of a positive selection. We detected highly divergent segments in wild S. lycopersicum species, and footprints of introgressions in crop accessions originating from a common donor accession. Phylogenetic relationships of fruit diversification and growth specific genes from crop accessions show incomplete resolution and are dependent on the introgression donor. In contrast, whole genome SNP information has sufficient power to resolve the phylogenetic placement of each accession in the four main groups in the Lycopersicon clade using Maximum Likelihood analyses. Phylogenetic relationships appear correlated with habitat and mating type and point to the occurrence of geographical races within these groups and thus are of practical importance for introgressive hybridization breeding. Our study illustrates the need for multiple reference genomes in support of tomato comparative genomics and Solanum genome evolution studies., 4 Figure, 10 Supplementary Figures, 2 Supplementary Figures This is the pre-peer reviewed version of the following article: The Plant Journal 80.1 (2014): 136-148, which has been published in final form at http://doi.org/10.1111/tpj.12616

Next to pollen, stamens of flowering plants often produce microstructures, called orbicules, lining the locules. Although the existence of orbicules has been known since 1865, their function still remains enigmatic. This paper surveys orbicule distribution throughout angiosperms, including +1,500 entries. We show that orbicules are found all over of flowering plants with an evolutionary trend towards orbicule absence in more derived clades. Orbicules are common in the ANITA-grade and 85 % of the monocots studied produce orbicules, with Orchidaceae, Commelinales and Zingiberales as notable exceptions. Within eudicots, asterids are most densely sampled with 61 % orbicule presence. Asteraceae and the majority of Lamiaceae lack orbicules. For 17 angiosperm orders orbicule distribution data are lacking entirely. We demonstrate that the hypothesized correlation of orbicule presence with non-amoeboid tapetum types holds true. The presence of orbicules is therefore a convenient proxy for tapetum characterization. The potential of orbicules as an a-cellular model system for patterned sporopollenin polymerization is discussed and suitable model plants for future functional orbicule-research are identified.