TAXONOMIC REVISION OF URVILLEA (SAPINDACEAE. PAULLINIEAE): AN AMERICAN GENUS

Background and aims: Urvillea Kunth is a small American genus of climbing shrubs or subshrubs, rarely erect subshrubs or rhizomatous hemicryptophytes. It is distributed from the southwestern United States to central Argentina, being Brazil the main center of diversity. Urvillea is characterized by its duodicogamy, trifoliated leaves and zygomorphic flowers; usually five sepals, four nectariferous lobes, anthers with a more or less conspicuous apical connective extension, and subchartaceous or chartaceous capsular fruits. Although some regional treatments are available, the only published comprehensive treatment of the genus was done by Radlkofer in 1932. The current work is the most up to date taxonomic revision of Urvillea based on modern collections and biosystematic studies. M&M: Taxonomic data were gathered from the literature, including phylogenetic studies, and from field observations, where specimens from 90 herbaria were analyzed. Morpho-anatomical observations were made with stereoscopic, optical and scanning electron microscope. Results: In this revision, 20 species of Urvillea are recognized. Most species have a wider geographical distribution than previously recognized. Nine names (eight at the species level and one form) are here lectotypified; in addition, four new synonyms are proposed. Furthermore, descriptions of pollen morphology are provided for all species.