A New Genus of Podostemaceae from Venezuela C. Thomas Philbrick and Jacqueline Malecki Department of Biological and Environmental Sciences, Western Connecticut State University, Danbury, Connecticut 06810, U.S.A. philbrickt@wcsu.edu Nicholas P. Tippery Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269-3043, U.S.A. Current address: Department of Biological Sciences, University of Wisconsin–Whitewater, 800 West Main Street, Whitewater, Wisconsin 53190, U.S.A. Hannah I. Stevens GIS Program Manager, New York Botanical Garden, 200th Street and Kazimiroff Boulevard, Bronx, New York 10458, U.S.A. ABSTRACT. The new genus Autana C. T. Philbrick es hermana de un clado que contiene especies de and species A. andersonii C. T. Philbrick are Castelnavia Tul. & Wedd., Oserya Tul. & Wedd., illustrated and described. The new species is Noveloa C. T. Philbrick y Rhyncholacis Tul.,ası´ como documented from four rivers that drain into the de especies con tallos erguidos de Apinagia Tul. y de Orinoco River, Amazonas, Venezuela. Autana is especies centroamericanas y mexicanas de Mara- distinguished by three characters that do not occur in thrum Bonpl. other Neotropical Podostemaceae. The upper surface Key words: Amazonas, aquatic plants, Autana, of the flattened stem has an anastomosing pattern that IUCN Red List, Podostemaceae, Venezuela. is derived from a continuation of leaf margins. When the capsule is mature, the pedicel apex (and Venezuela exhibits a rich diversity of Podostema- receptacle) is swollen and hollow. After anthesis, ceae. Vela ´squez (1994) recognized eight genera and locations where the deciduous stamens attached 22 species in the country. Philbrick et al. (2010) become darkened and shaped like an inverted listed the same genera, but somewhat more (28) teardrop. Phylogenetic analyses indicate A. ander- species. Berry (2004) reported 26 species for the sonii is sister to a clade containing species of Venezuelan Guayana alone. Six of the genera Castelnavia Tul. & Wedd., Oserya Tul. & Wedd., documented from Venezuela (Apinagia Tul., Jenma- Noveloa C. T. Philbrick, and Rhyncholacis Tul., as niella Engl., Marathrum Bonpl., Mourera Aubl., well as upright stemmed species of Apinagia Tul., Oserya Tul. & Wedd., Rhyncholacis Tul.) represent and Central American and Mexican species of the subfamily Podostemoideae, while two otherwise Marathrum Bonpl. occur in the Weddellenoideae (Weddellina Tul.) or RESUMEN. Se ilustran y describen un ge ´nero Autana Tristichoideae (Tristicha Thouars) (Royen, 1951, C. T. Philbrick y una especie A. andersonii C. T. 1953, 1954). The current contribution adds an Philbrick nuevos. La especie nueva se registra de additional genus to Venezuelan Podostemaceae. cuatro r´ ıos que desembocan en el r´ ıo Orinoco, While conducting field studies along tributaries of Amazonas, Venezuela. Autana se distingue de otras the Orinoco River (Venezuela, Amazonas), specimens Podostemaceae por tres caracteres que no se were collected that did not correspond to any of the encuentran en ninguna de las otras especies de presently recognized species or genera in the Podostemaceae neotropicales. La superficie superior Podostemaceae. The new taxa described here belong del tallo aplanado tiene una figura anostomosada que to the Podostemoideae based on the presence of a surge de una continuidad de los ma ´rgenes de la hoja. spathella surrounding the flower, a 2-carpellate Cuando la ca ´ psula se madura, el a ´ pice del pedicelo (y ovary, two stigmas, and distichous leaves. Molecular recepta ´culo) se hincha y se torna hueco. Los sitios studies (ITS, rbcL, trnL) of Neotropical Podostema- donde los estambres caedizos estaban unidos, se ceae indicate that the new species is distinct from all oscurecen y toman la forma de una la ´grima invertida. other taxa in subfamily Podostemoideae (Tippery et Los ana ´lisis filogene ´ticos indican que A. andersonii al., 2011, listed as ‘‘Autana,’’ see below). Conse- doi: 10.3417/2010051 NOVON 21: 475–480. PUBLISHED ON 29 DECEMBER 2011.