Gomphocarpus, placed in the Apocynaceae family is a genus of milkweeds first described as a genus in 1810. It is widespread across much of Africa, with a few species naturalized in other regions. The generic name is derived from the Latin words, gompho, meaning club and carpus, meaning fruit, in reference to the shape of the fruit.

Gomphocarpus rivularis, synonymously known as Asclepias rivularis and commonly known as River Milkweed, is a widespread South African indigenous evergreen shrub often found growing on the Indian Ocean belt along riverbanks and inland towards Gauteng and Swaziland. During winter it produces clusters of cream to peach coloured flowers which attract butterflies.