21. Rhabdadenia Müller Arg. in C. F. P. von Martius et al., Fl. Bras. 6(1): 173, plate 52. 1860.
[Derivation uncertain; Greek rhabdos, rod, and aden, gland]
David E. Lemke
Woody vines [subshrubs]; latex milky. Stems twining to suberect, unarmed, glabrous. Leaves persistent, opposite, petiolate; stipular colleters present but early-deciduous, interpetiolar; laminar colleters absent. Inflorescences axillary or subterminal, cymose, pedunculate. Flowers: calycine colleters absent; corolla white to pinkish white with yellow throat, occasionally dark pink toward base [pink, magenta], funnelform, aestivation dextrorse; corolline corona absent; androecium and gynoecium not united into a gynostegium; stamens inserted near top of corolla tube; anthers connivent, adherent to stigma; connectives enlarged, 2-lobed, locules 4; pollen free, not massed into pollinia, translators absent; nectaries 5, distinct or basally connate, alternating with stamens. Fruits follicles, usually paired, erect, brown, slender, terete or compressed, surface striate or smooth, glabrous. Seeds linear, flattened, not winged, beaked, comose, not arillate.
Species 3 (1 in the flora): Florida, Mexico, West Indies, Central America, South America.
Rhabdadenia has one of the broadest ranges of neotropical Apocynaceae, extending from the southeastern United States (Florida), West Indies, and Mexico to northern Argentina, the species typically inhabiting mangrove swamps or other flooded habitats (J. F. Morales 2009).
SELECTED REFERENCE Morales, J. F. 2009. Estudios en las Apocynaceae neotropicales XXXVII: Monografía del género Rhabdadenia (Apocynoideae: Echiteae). J. Bot. Res. Inst. Texas 3: 541–564.
