Euphorbia dregeana plants grow in the Richtersveld, Namaqualand and in Namibia. It is commonly called elephant’s bush and dikboud in Afrikaans. The flowers are yellow with two rounded petal-like lobes encircling the emerging six-sectioned seed capsule. The capsule turns red when developed and brown later when it dries. The plant exudes the characteristic Euphorbia white latex, sometimes called wolves’ milk.
A rare root parasitic angiosperm, Hydnora triceps, lives on Euphorbia dregeana plants exclusively (Wikipedia).