The genus name was derived from the Greek words rhombos, meaning lozenge and phyllon, meaning leaf, in reference to the somewhat rhomboidally shaped leaves. The plants flower in spring and early summer. The flowers open in the afternoon or evening. The rather strange and outlandish appearance of the species of Rhombophyllum, make them some of the more desirable mesembs to grow.

Rhombophyllum rhomboideum, the diamond-leaved rhombophyllum, is a species of flowering plant in the family Aizoaceae, native to the eastern Cape Provinces of South Africa. A succulent, it has gained the Royal Horticultural Society’s Award of Garden Merit. Syn. Bergeranthus rhomboideus, Mesembryanthemum rhomboideum, Rhombophyllum rhomboideum var. groppiorum. This is an endangered species where it natural habitat is threatened by development of the Coega Harbour.