A Taxonomic Treatment of Rogiera (Guettardeae, Rubiaceae)

Abstract

Abstract—Rogiera (Guettardeae, Rubiaceae) is a Neotropical genus distributed from Mexico to northern South America that includes shrubs, treelets, or trees, which were previously treated in the taxonomically controversial and confused Rondeletia complex. Rogiera can be recognized among other Rubiaceae by the combination of multiflowered inflorescences, heterostylous flowers, quincuncial corolla aestivation, a hairy ring at the corolla mouth, and capsular fruits with loculicidal dehiscence. Despite the recent taxonomic circumscription of Rogiera there is not a comprehensive taxonomic treatment to it. Moreover, regional floristic treatments disagree on the species circumscriptions, with discrepancies in the number of species of Rogiera from 11 to 20. Based on molecular and morphological evidence studied on field and herbarium specimens, we present a taxonomic revision of Rogiera. We recognize ten species; Mexico is the center of diversity with nine species, four of them endemic. An identification key, descriptions, distribution maps, nomenclatural history, phenological data, and illustrations of all the species in the genus are provided for the first time. Several names required lecto- or epitypifications designated here.