Smith, G.F. (2023) In search of enhanced material: Kalanchoe ×toelkenii (Crassulaceae subfam. Kalanchooideae), a new South African nothospecies derived from Kalanchoe ×gunniae × K. sexangularis. Phytotaxa 619 (3): 241–249. https://doi.org/10.11646/phytotaxa.619.3.4