6 351757 Discocactus placentiformis (Lehm.) Schumann [125 171896 Cactus placentiformis Lehm.] Cactaceae
L.K.G. Pfeiffer, F. Otto, Abbild. Beschr. Cact. (Coloured version), vol. 2 : p. 1, t. 1 (1839)