Petalidium coccineum used to be called P. rubescens. Petalidium refers to petals and coccineum to the scarlet colour of the flower’s five petals. The plant is a shrubby scrambler from the northern parts of Namibia, particularly the Kaokoveld and Ovamboland.

The kaoko petalidium has the curious name of rooi-tongklapper (red tongue cracker) in Afrikaans. This was derived from the feature of the seeds to explode like crackers when moist. A children’s game of placing the seed capsules under the tongue, waiting for them to crack open with noisy action, brought about the name (www.plantzafrica.com).