Euphorbia rudis showing cyathia

The cyathia or pseudo-flowers of Euphorbia rudis grow on a fairly long peduncle or stalk. These peduncles emerge from the axils of the leaves, between the tubercles at the stem tops. The peduncles may be simple or once branched. Scattered bracts can be seen along the peduncle, below the involucre.

Cyathium means cup, the general structure of Euphorbia inflorescences. The cyathia structure has at its base an involucre, a kind of wrapper or envelop, in the form of a bract or combination of bracts. A few concave, green-topped glands surrounded by a fringe of tiny yellow protuberances can be seen. The yellow, three-branched style is in the centre.

The capsules of Euphorbia, the fruits that contain the seeds, dehisce or break open explosively for the release of the seeds. Fruits containing only one seed do not dehisce, because there is no need to spread a single seed; much need exists to distribute a multitude of them. Some dry, three-chambered capsules, swollen versions of the ovaries that formed part of the female cyathia, are visible in the photo (Williamson, 2010; JSTOR; iSpot).