Family LamiaceaeRotheca hirsuta occurs mainly in grassland. It is one of the first spring flowers to appear after winter in the summer rainfall regions.
Rotheca hirsuta is a perennial herb with many, erect, unbranched, angular, annual stems arising from an underground rootstock. The stems are mostly up to 0.3 m high, rarely up to 0.5 m. The sessile leaves of R. hirsuta are arranged in whorls of three, sometimes four, rarely opposite. The shape of the blade varies from narrowly oblong, narrowly obovate, narrowly elliptic, elliptic to broadly elliptic, with an acute apex and entire margin. The leaf blades are totally glabrous and smooth to densely hairy and often somewhat succulent. The surfaces of the leaf blade are often described in the literature as glandular-punctate. A study of the leaf surfaces with the scanning electron microscope revealed that there are actually numerous peltate hairs covering the leaf surface.
The white, inverted Y-shaped pattern on the lower corolla lip and the long exserted, curved stamens and style of Rotheca hirsuta are adaptations to insect pollination. With sturdy, often very old, fire-resistant rootstocks, this species is well adapted to survive unfavourable conditions.
Uses and cultural aspects
The Sotho people administered a decoction of the root as an enema in kidney disease ( Phillips 1917; Watt & Breyer-Brandwijk 1962; Jacot Guillarmod 1971; Lucas & Pike 1971 ). An infusion made from the roots and leaves is used as a remedy for worms by the Zulu (Hulme 1954; Walker 1996). According to Hutchings et al. (1996) roots are used in medicines known as imbiza yomzimba omubi which are taken for scrofula swellings and root and leaf infusions are taken as anthelmintics by the Zulus.