Unusual Cyphostemma (Vitaceae) in Namibia: Natural Hybrids or a New Species?

摘要

Dlants of the genus Cyphostemma (Planch.) Alston (Vitaceae), carved out of Cissus L. on the basis of flower features by Descoings (Descoings, 1967), are distributed over much of mainland Africa and the Mascarene Islands, particularly Madagascar. Mostpopular in cultivation are the pachycaul species, a minority amongst many climbers. There are several unde-scribed taxa from northern Kenya, the Ogaden and north-eastern Somalia, as well as the popular C. betiforme (Chiov.) Vollessen, which is widespreadin northeast Africa. Most frequently encountered in cultivation however, are those from Namibia: C. currorii (Hook.f.) Desc. (Hooker, 1849), C.juttae (Dinter 8c Gilg) Desc. (Dinter 8c Gilg, 1912), C. seitzianum (Gilg 8c M. Brandt) Desc. (Gilg 8c Brandt, 1911-1912) and C. uter (Exell 8c Mendonca) Desc. (Exell 8c Mendonca, 1952). They are cherished by collectors for their bizarre fat-trunked forms, and also make valuable additions to the water-wise landscape in suitable climates.