Thomasia is a genus of about 32 species, all occurring in Western Australia with one (Thomasia petalocalyx) also extending to South Australia and Victoria. Thomasias are generally small to medium shrubs in which the calyx of the flower is more prominent than the petals. The genus is closely related to Guichenotia, Lasiopetalum and Lysiosepalum.
Thomasia rhynchocarpa is a small, often erect shrub from 0.5 to 1.5 metres in height. The dull green leaves are rough and broadly oblong in shape to about 45 mm long. The pink to purple flowers occur in late winter and spring and are very conspicuous. They are about 10 mm in diameter and are followed by capsules containing black seeds which are shed from the plant when ripe.
T.rhynchocarpa is reasonably popular in cultivation and seems to be hardy in most temperate areas provide soils are well drained. It is less hardy in sub-tropical to tropical areas. It grows best in a semi-shaded position but will tolerate full sun.
Propagation can be carried out from seed but germination can be unreliable. Cuttings of firm, current season’s growth usually strike reliably.
Photo: Brian Walters