Hypocalymma is a small genus of about 29 species, all of which occur naturally only in south Western Australia. H.angustifolium and H.cordifolium are the best known members of the genus and are widely cultivated. H.speciosum is a small, spreading shrub from 0.5 to 1.5 metres high with oval-shaped leaves about 15 mm long. In late winter and spring the deep pink flowers appear in clusters along the stems. Individually the flowers are about 10 mm in diameter.
This species is a very attractive garden plant but is not widely available. On the basis of limited experience, it seems to be adaptable to a range of climates including humid, east-coastal areas where other species from the south west are often difficult to maintain. The plant requires moist, well drained conditions and seems to prefer dappled shade, but will tolerate more exposed positions, and it is tolerant of at least moderate frost. Annual pruning will help maintain a dense, bushy growth habit.
Propagation can be carried out from seed and, based on experience with the related H.angustifolium, improved germination may be achieved using smoked water. Propagation from cuttings is the preferred method and cuttings strike readily from hardened, current season’s growth.
Photo: Tony Cavanagh