A taxonomic synopsis of Virola (Myristicaceae) is presented for Mesoamerica. Fourteen species are recognised, amongst them six are described and published as new, based on morphology: V. allenii D.Santam. & Aguilar, sp. nov. from Costa Rica, V. otobifolia D.Santam., sp. nov. from Panama and V. amistadensis D.Santam., sp. nov., V. chrysocarpa D.Santam. & Aguilar, sp. nov., V. fosteri D.Santam., sp. nov. and V. montana D.Santam., sp. nov. from both Costa Rica and Panama. Additionally, a lectotype is designated for V. koschnyi, accompanied by an epitype in view of the fragmentary material. Finally, we recognise V. laevigata and V. nobilis as morphologically distinct species, though these are frequently considered synonymys of V. guatemalensis and V. surinamensis, respectively. Of the fourteen accepted species, twelve of them are endemic to Mesoamerica, while the remaining two species (V. elongata and V. sebifera) extend into South America. Illustrations, species diagnoses and distribution maps for each species are provided, as is an identification key to all species.

La Amistad International Park is a World Heritage Site, which comprises 401,000 ha of mainly upland continuous natural vegetation straddling the Costa Rica and Panama border. We present a first checklist of vascular plant diversity for the park and a brief discussion of how this diversity is distributed by elevation and vegetation type together with a superficial assessment of floristic affinities. The checklist recognises 3,046 vascular plant species, 26 of which are lycopods, 433 are ferns and 2,586 are seed plants. Of these, 16 are new records for Costa Rica and 39 are for the flora of Panama; 14 represent undescribed or new species to science and 73 are endemic to La Amistad or its buffer zone. For each species we document its presence within the Park by citing herbarium specimens and the associated elevational range, together with their global distribution, extinction risk assessments where undertaken, whether the taxon is exotic.

Aim Plant distributions are influenced by species’ ability to colonize new areas via long‐distance dispersal and propensity to adapt to new environments via niche evolution. We use otobas, a clade of ecologically dominant trees found in low‐to mid‐elevation wet forests, as a system to understand the relative importance of these processes within the Neotropics. Location Neotropics and global. Taxon Otoba and entire Myristicaceae. Methods We resolve the first phylogeny of Otoba the Angiosperms353 loci and plastome sequences from 13 accessions representing seven species. We pair this with the most densely sampled phylogeny of Myristicaceae to date, inferred using publicly available plastid data. We then use environmental niche modelling, biogeographical reconstruction, phylogenetic principle components analysis and Ornstein–Uhlenbeck models to infer biogeography and examine patterns of niche evolution. Results Myristicaceae has an Old World origin, with a single expansion into the Americas. Divergence dates, fossil evidence and a notable lack of long‐distance dispersal are consistent with a Boreotropical origin of Neotropical Myristicaceae. Mirroring the rarity of dispersal at the family level, Otoba's biogeography is marked by few biogeographical events: two expansions into Central America from a South American ancestor and a single dispersal event across the Andes. This limited movement contrasts with rapid climatic niche evolution, typically occurring across geographically proximate habitats. Main conclusion Contrasting with previous studies, long‐distance dispersal does not need to be invoked to explain the pantropical distribution of Myristicaceae, nor the biogeography of Otoba. This likely results from the family's relatively large seeds that are dispersed by large‐bodied vertebrates. Instead, rapid niche evolution in Otoba has facilitated its occurrence throughout mesic habitats of the northern Neotropics, including the Amazon rainforest and Andean montane forests. Otoba adds to a growing group of Neotropical plant clades in which climate adaptation following local migration is common, implying an important role of niche evolution in the assembly of the Neotropical flora.

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