Oscularia deltoides is an easy-to-grow, succulent groundcover, ideal as an accent plant and for low-maintenance and water-wise gardens.
Oscularia deltoides is a robust, trailing perennial shrublet. The stems are succulent and reddish. The leaves are characteristically three-angled, sickle-shaped and grey-green, often tinged red in the drier season. This species is easily distinguished from the others as it is the only one with the leaf margins and keel prominently red-toothed.
The scented flowers are mainly pink and are produced in the early summer (October-December) and open in the afternoons. Stamens, being white below and pink above, are collected into a cone in the centre of the flower. Fruits repeatedly open when wet and close when dry.
Oscularia deltoides is not regarded as threatened in its native habitat.
Distribution and habitat
Oscularia deltoides occurs almost exclusively on sandstone rocks, ranging along the mountains from Ceres to George, but is, however, absent from the Cape Peninsula.
Derivation of name and historical aspects
Osculum (Latin), means small mouth. Oscularia therefore means a group of small mouths and refers to the toothed leaves of Oscularia deltoides.
There are currently 28 names available in the genus, although a number of these are undoubtedly superfluous.
The genus is confined to the winter rainfall areas of the Western Cape and can be said to prefer sandstone outcrops, although a number of species also occur on granite.
Oscularia deltoides almost invariably occurs alone in rocky habitats. This could indicate intolerance to competition by other plants or could also be an escape mechanism from the frequent fires in the Fynbos.
Uses and cultural aspects
Oscularia deltoides is widely used in horticulture, both locally and internationally. It come from mostly frost free areas, but may be tolerant of occasional very mild frost.
Growing Oscularia deltoides
Plants are easily cultivated from cuttings and are well suited to sunny rockeries and steep embankments or as an accent plant in pots. Cuttings are best rooted when planted in sand, but can also be planted directly in the required beds. Seeds should be sown during autumn in winter rainfall areas.
- Germishuizen, G., Meyer, N.L., Steenkamp, Y. & Keith, M. (eds) 2006. A Checklist of South African plants. Southern African Botanical Diversity Network Report No. 41. SABONET, Pretoria.
- Smith, G.F., Chesselet, P., Van Jaarsveld, E.J., Hartmann, H.E.K., Hammer, S., Van Wyk, B-E., Burgoyne, P.M., Klak, C. & Kurzweil, H. 1998. Mesembs of the world. Briza Publications, Pretoria.
Matt H. Buys
To find out if SANBI has seed of this or other SA species, please email our seedroom