Amphidasya Standl. (Rubiaceae: Rubioideae) Charlotte M. Taylor [webpage] Missouri Botanical Garden P.O. Box 299 St. Louis, MO 63166 Amphidasya ambigua in Colombia Amphidasya Standl. includes at least 13 species of low shrubs and suffrutescent herbs found in wet neotropical forests of Central America and northern South America. Amphidasya can be recognized by its opposite, often rather large leaves, its interpetiolar stipules that are usually deeply laciniate to fimbriate, its flowers several in pseudoaxillary (i.e., lateral) cymes, its salverform white corollas with slender long tubes, and its fleshy to dry small fruits. The flowers are homostylous, and nocturnal in at least some species. The anthers usually have the connective prolonged into an apical appendage. The corolla lobes are valvate in bud, and are often ornamented with multicellular, tuberculate to filamentous appendages on their margins and sometimes also their adaxial (i.e., internal) faces. In many species the calyx lobes persist on the fruits and enlarge markedly as they develop. The stipules that are deeply divided into narrow segments are unusual in Rubiaceae and distinctive. Amphidasya was separated out from Sabicea Aubl. by Standley in 1936, and has been classified by most authors together with Sabicea in the Isertieae of the subfamily Cinchonoideae. However, the tissues of Amphidasya contain raphides, while other genera of Isertieae lack these. Recent studies based on molecular data suggest Amphidasya is better placed in the subfamily Rubioideae, and may be related to the paleotropical genus Pauridiantha Hook.f. (Bremer & Thulin, 1998; Rova et al., 1999). Pauridiantha is generally classified in the Pauridiantheae, a Paleotropical tribe of genera with raphides and simple triangular stipules. The species and circumscription of Amphidasya have been reviewed recently by Steyermark (1972) and Taylor & Clark (2001); a key to all of the species of Amphidasya is presented by Taylor & Clark (2001: pp. 490-491). References Bremer, B. & M. Thulin. 1998. Collapse of Isertieae, re-establishment of Mussaendeae, and a new genus of Sabiceeae (Rubiaceae): Phylogenetic relationships based on rbcL data. Pl. Syst. Evol. 211: 71-92. Rova, J.H.E., P.G. Delprete, L. Andersson, & V.A. Albert. 1999. Rubiaceae phylogeny based on trnL-F sequence data. In: J.H.E. Rova, The Rondeletieae-Condamineeae-Sipaneeae Complex (Rubiaceae) 1: 1-35. Gothenburg University, Sweden. Steyermark, J.A. 1972. Amphidasya. In: B. Maguire & Collaborators, Flora of the Guayana Highland. Mem. New York Bot. Gard. 23: 316-322. Taylor, C.M. & J.L. Clark 2001. Rubiacearum Americanarum Magna Hama V. Amphidasya in Mesoamerica and western South America. Novon 11: 489-497. TOP List of Names and Synonyms of Amphidasya The following list is based on a review of this genus by Taylor & Clark (2001). Accepted names are presented in bold; synonymous names appear with an equals sign. Further information on these names can be found in the TROPICOS database [http://www.tropicos.org/]. Amphidasya ambigua (Standl.) Standl., eastern Panama to Ecuador Amphidasya amethystina J.L. Clark & C.M. Taylor, northwestern Ecuador Amphidasya brevidentata C.M. Taylor, western Colombia Amphidasya bullata Standl., western Colombia to northwestern Ecuador Amphidasya colombiana (Standl.) Steyerm., Colombia to northern Peru Amphidasya elegans Standl., western Colombia to northwestern Ecuador Amphidasya intermedia Steyerm., Colombia Amphidasya longicalycina (Dwyer) C.M. Taylor, southern Nicaragua to northwestern Colombia Amphidasya neblinae Steyerm., eastern Venezuela Amphidasya panamensis C.M. Taylor, Panama Amphidasya spathulata Dwyer, Panama to northwestern Colombia Amphidasya umbrosa (Wernham) Standl., northwestern Colombia Amphidasya venezuelensis (Standl.) Steyerm., northern Venezuela Deppea colombiana Standl. = A. colombiana Deppea venezuelensis Standl. = A. venezuelensis Hoffmannia longicalycina Dwyer = A. longicalycina Pittierothamnus elineolatus Steyerm. = A. venezuelensis Sabicea ambigua Standl. = A. ambigua Sabicea umbrosa Wernham = A. umbrosa Text and Images, unless otherwise indicated, Copyright © by Charlotte M. Taylor. All rights reserved. This page was revised on April 8, 2008. TOP