Brachystelma

Brachystelma is a genus of perennials, mainly dwarf plants in the Apocynaceae or milkweed family. They exuding a milky latex. The generic name, Brachystelma, is derived from the Greek words brachys meaning short and stelma meaning crown, referring to the usually quite small corona present in the flower centre.

The plants grow from a single, disc-shaped to nearly globose tuber, or from a cluster of spindle-shaped, fleshy roots. One or more stems, creeping or erect may be grown by a plant, the stems sometimes twining. The simple leaves may have petioles or not.

The flowers grow in stem-tip umbels or umbel-like cymes, also from stem nodes, solitary or in clusters. The individual flowers have pedicels, the flower clusters may have short peduncles. The five sepals often have scales on their inside surfaces.

The five-lobed corollas are nearly flat, bell-shaped or shortly tubular, the tubes shorter than the lobes. These lobes spread or are joined at their tips in a cage-like structure.

The corona arises from the staminal column in the flower centre, occurring in two series, inner and outer. The outer corona is variously five-lobed or ten-teethed (or mini-lobed), the inner corona one smaller-lobed, the lobes opposite the anthers, often linear but in few cases club-shaped. The anthers have two locules, positioned on the staminal column or erect, without appendages, the pollinia variously rounded. Some species are odourless, others exude putrid smells.

The fruits are erect, spindle-shaped follicles, usually green but sometimes mottled. The seeds are oblong and sometimes convex on one side with a marginal wing and hair tuft at one end.

There are more than 100 species of Brachystelma occurring in Africa, Asia and Australia, about 80 of which found in southern Africa.

The swollen tubers are often edible by people and certain animals, sometimes referred to as a famine food. Some species are keenly collected by gardeners and traditional healers, several species are threatened in nature.

The plant in picture is Brachystelma stellatum (Leistner, (Ed.), 2000; Wikipedia).