The climbing species of Ficus : derivation and evolution

Abstract

Climbers have arisen independently in three groups of Ficus. They have specialized leptocaul progress in two ways. The strangling habit has been modified into epiphytic climbing in subgen. Urostigma (5 spp. of climber) and subgen. Ficus sect. Sycidium subsect. Palaeomorphe (4 spp. of climber). The systematic origin of these nine species is fairly clear. F. subulata is a stoloniferous climber building epiphytic thickets. In contrast, ground-based root-climbing with the evolution of bathyphylls distinguishes the whole of subgen. Ficus sect. Rhizocladus (57 spp.) and sect. Kalosyce (20 spp.). Their origin is not clear. The more pachycaul Bornean F. spiralis suggests derivation from the ancestry of sect. Ficus ser. Cariceae and ser. Podosyceae by modification of the pachycaul tree. Stranglers apart, fig-climbers appear to be an Indo-Malesian distinction. F. rhopalosycia Diels is redescribed.