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Taxonomic treatments of Pilosocereus in the Andean and Caribbean regions have varied widely. Recent authors often recognized three species only (P. lanuginosus, P. polygonus, and P. royenii), while Britton & Rose in 1920 (sub Cephalocereus) recognized 18 species in the same region. A revision of Pilosocereus is necessary, and it was carried out by the study of both herbarium specimens and living plants. Twelve species of Pilosocereus are recognized in the present paper for the Andean and Caribbean regions, including one new combination, i.e. P. curtisii, and one new species, i.e. P. jamaicensis. Typifications are provided for several names, including the Linnaean basionym Cactus royenii. Morphological descriptions, distributions, and an identification key of the recognized species are provided.

Extinction rates are expected to increase during the Anthropocene. Current extinction rates of plants and many animals remain unknown. We quantified extinctions among the vascular flora of the continental United States and Canada since European settlement. We compiled data on apparently extinct species by querying plant conservation databases, searching the literature, and vetting the resulting list with botanical experts. Because taxonomic opinion varies widely, we developed an index of taxonomic uncertainty (ITU). The ITU ranges from A to F, with A indicating unanimous taxonomic recognition and F indicating taxonomic recognition by only a single author. The ITU allowed us to rigorously evaluate extinction rates. Our data suggest that 51 species and 14 infraspecific taxa, representing 33 families and 49 genera of vascular plants, have become extinct in our study area since European settlement. Seven of these taxa exist in cultivation but are extinct in the wild. Most extinctions occurred in the west, but this outcome may reflect the timing of botanical exploration relative to settlement. Sixty‐four percent of extinct plants were single‐site endemics, and many occurred outside recognized biodiversity hotspots. Given the paucity of plant surveys in many areas, particularly prior to European settlement, the actual extinction rate of vascular plants is undoubtedly much higher than indicated here., Article impact statement: The number of presumed extinct plants from the continental United States and Canada is much greater than previously recognized.

Evans and Davis claim the SER Standards use a “pure naturalness” model for restoration baselines and exclude most cultural ecosystems from the ecological restoration paradigm. The SER Standards do neither. The SER Standards consider both “natural” ecosystems (that are unequivocally not cultural) and “similar” cultural ecosystems as suitable reference models. Furthermore, Evans and Davis propose assessing whether a cultural ecosystem exhibits “good, bad, or neutral impacts from humans on ecosystems” as the basis for reference models. We argue that such an approach would overlook the indispensability of native ecosystem benchmarks to measure human impacts and provide a springboard for social‐ecological restoration.

As part of ongoing efforts to understand and document the flora of the southeastern United States, a number of taxonomic changes at generic, specific, and infraspecific rank are made. We also discuss and clarify the recommended taxonomy for other taxa (not requiring nomenclatural acts) and present a point of view about the practical and philosophic basis for making taxonomic changes in an allegedly well-understood flora. The genera (and families) affected are Allium (Alliaceae), Erigeron, Liatris, and Trilisa (Asteraceae), Calycanthus (Calycanthaceae), Gaylussacia (Ericaceae), Dalea and Mimosa (Fabaceae), Hydrophyllum (Hydrophyllaceae), Didymoglossum (Hymenophyllaceae), Monarda (Lamiaceae), Kosteletzkya and Sida (Malvaceae), Narthecium (Nartheciaceae), Agalinis, Melampyrum, and Orobanche/Aphyllon/Myzorrhiza (Orobanchaceae), Dichanthelium and Elymus (Poaceae), Clematis (Ranunculaceae), and Maianthemum (Ruscaceae).

Natural environmental gradients provide important information about the ecological constraints on plant and microbial community structure. In a tropical peatland of Panama, we investigated community structure (forest canopy and soil bacteria) and microbial community function (soil enzyme activities and respiration) along an ecosystem development gradient that coincided with a natural P gradient. Highly structured plant and bacterial communities that correlated with gradients in phosphorus status and soil organic matter content characterized the peatland. A secondary gradient in soil porewater NH4 described significant variance in soil microbial respiration and β-1-4-glucosidase activity. Covariation of canopy and soil bacteria taxa contributed to a better understanding of ecological classifications for biotic communities with applicability for tropical peatland ecosystems of Central America. Moreover, plants and soils, linked primarily through increasing P deficiency, influenced strong patterning of plant and bacterial community structure related to the development of this tropical peatland ecosystem.

A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups., La lista completa de autores que integran el documento puede consultarse en el archivo., Facultad de Ciencias Naturales y Museo

Aunque el Estado de Florida (Estados Unidos) ha adoptado las directrices de la UICN en cuanto a la aplicación de los criterios de conservación relacionados a su fauna, existe un vacío en términos de que ciertas especies pueden ser protegidas a pesar de no encontrarse en la lista de especies amenazadas y recibir algún nivel de protección. El Parque Nacional Everglades (Florida) es un hábitat crítico para un número de especies raras y otras varias docenas enlistadas como En Peligro o Amenazadas. Sin embargo, un dilema es la interacción entre especies. En este caso, la mosca endémica Melanagromyza miamensis oviposita sus huevos en la inflorescencia de la orquídea Trichocentrum undulatum. En ella, las larvas se desarrollan gen- eralmente matando al tallo. Este es un ejemplo de la interacción entre dos especies, una ampliamente dis- tribuida pero localmente incluida bajo la categoría de Críticamente Amenazada (CR) (T. undulatum) y la especie endémica (M. miamensis). De esta manera, se utiliza este ejemplo para demostrar la complejidad en el desarrollo de un plan de manejo. Aunque el Estado de Florida (Estados Unidos) ha adoptado las directrices de la UICN en cuanto a la aplicación de los criterios de conservación relacionados a su fauna, existe un vacío en términos de que ciertas especies pueden ser protegidas a pesar de no encontrarse en la lista de especies amenazadas y recibir algún nivel de protección. El Parque Nacional Everglades (Florida) es un hábitat crítico para un número de especies raras y otras varias docenas enlistadas como En Peligro o Amenazadas. Sin embargo, un dilema es la interacción entre especies. En este caso, la mosca endémica Melanagromyza miamensis oviposita sus huevos en la inflorescencia de la orquídea Trichocentrum undulatum. En ella, las larvas se desarrollan gen- eralmente matando al tallo. Este es un ejemplo de la interacción entre dos especies, una ampliamente dis- tribuida pero localmente incluida bajo la categoría de Críticamente Amenazada (CR) (T. undulatum) y la especie endémica (M. miamensis). De esta manera, se utiliza este ejemplo para demostrar la complejidad en el desarrollo de un plan de manejo.

Many of the skills and resources associated with botanic gardens and arboreta, including plant taxonomy, horticulture, and seed bank management, are fundamental to ecological restoration efforts, yet few of the world's botanic gardens are involved in the science or practice of restoration. Thus, we examined the potential role of botanic gardens in these emerging fields. We believe a reorientation of certain existing institutional strengths, such as plant-based research and knowledge transfer, would enable many more botanic gardens worldwide to provide effective science-based support to restoration efforts. We recommend botanic gardens widen research to include ecosystems as well as species, increase involvement in practical restoration projects and training practitioners, and serve as information hubs for data archiving and exchange.