Euphorbia gregaria in desert habitat

The Euphorbia genus comprises several species that thrive in the semi-desert conditions of the north-west of South Africa. One such species is Euphorbia gregaria, commonly known as the Karas euphorbia, sometimes as the broom euphorbia. It grows in the south of Namibia and in the Richtersveld. Unlike many local Euphorbia species this one is dioecious, male and female cyathia growing on separate plants.

E. gregaria becomes a dense, rounded to spreading shrub comprising many cylindrical, spineless stems, reminding of E. mauritanica. The stems are blue-green or yellow-green to pale grey in colour. The plant is deciduous, having its leaves only for a short while on new growth. Small scars remain where they drop off. 

This species blooms from the end of winter to mid-spring and again sometimes in autumn. A couple of involucral bracts and some hairiness are found below the female flowers. The fruit is a globose, segmented capsule hanging from a curved stalk (JSTOR; www.treeatlas.biodiversity.org.na).