Remusatia vivipara

Description

Remusatia vivipara (Roxb.) Schott is a widespread tuberous aroid of the Old World tropics, the most broadly distributed member of its genus, with nearly 790 records spanning the Himalaya and India, China and Taiwan, Southeast Asia, Indonesia and Australia, tropical Africa and Madagascar, and Arabia, plus naturalised occurrences elsewhere. It is chiefly an epiphyte and lithophyte on mossy tree trunks, cliffs and boulders in humid forest, descending into shaded ravines and persisting in disturbed semi-shade. The cited gatherings from Galephug in southern Bhutan at 600 m in October and the Mewa Khola of East Nepal at 1900 m in April span its lowland-to-submontane range.

The plant grows from a small depressed-globose tuber that gives rise annually to one or few leaves and to the conspicuous bulbiliferous shoots characteristic of the genus. The leaf blade is ovate to ovate-cordate and peltate, on a long sheathing petiole. Dispersal is dominated by erect, spike-like bulbil-bearing axes densely set with small, scale-covered bulbils armed with recurved hooks that catch on the fur and feathers of passing animals. Flowering, where it occurs, produces a spathe with a basal convolute tube and expanded limb, subtending a spadix with separate female and male zones; sexual reproduction is much less frequent than vegetative propagation.

The extraordinary pantropical range of R. vivipara is largely attributable to this epizoochorous bulbil dispersal, supplemented by human movement of ornamental and tuber stock. Its placement in Colocasieae, near Colocasia and Gonatanthus, has been confirmed by molecular work. The species is common, ecologically plastic and locally weedy, and is of no conservation concern; in cultivation it is valued as a curious bulbil-producing aroid.

Author: (Roxb.) Schott · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Flora of Nepal, monograph of Remusatia and tribe Colocasieae