Coccoloba burkeae and C. najarroi, two new species of Coccoloba sect. Coccoloba (Polygonaceae) from Mexico

Abstract

Background: Coccoloba is a Neotropical genus of trees, shrubs, and lianas with approximately 150 species. Reviwed Mexican specimens of Coccoloba do not correspond to any recognized species within the genus, so they are proposed as new species. Question: What are the morphological characteristics that differentiate the two new species from other Coccolobaspecies? What is its distribution and conservation status? Studied species: Species of Coccoloba sect. Coccoloba endemic to Mexico. Study site and dates: Chiapas and Veracruz, Mexico, 2022-2023. Methods: All available information for Coccoloba, including herbarium specimens and online databases, was reviewed. Subsequently, a comparative analysis was carried out including the two new species proposed and the recognized species in the genus. Geographic distribution maps were prepared and the conservation status of the new species was determined, following the IUCN guidelines. Results: Coccoloba burkeae and C. najarroi are described and illustrated as new species. Both are endemic to Mexico. C. burkeae is distributed in the humid forests of the Tuxtlas region in Veracruz and is morphologically similar to C. barbadensis, C. hondurensis and C. spicata; this species is considered in the Endangered (EN) category. C. najarroi is restricted to the humid forests of Chiapas and is similar to C. ascendens and C. ibarrae. This species is considered Critically Endangered (CR). Conclusions: The morphological characteristics of the fruit, the inflorescence and the leaves are important to diagnose the two new species of Coccoloba; both being endemic to Mexico.