Crouch, Neil R., and Gideon F. Smith. 2023. “Cotyledon mckayi (Crassulaceae Subfam. Kalanchooideae), a New Cremnophytic Species from the Central Tugela River Basin of KwaZulu-Natal, South Africa”. Phytotaxa 632 (2). Auckland, New Zealand:184-92. https://doi.org/10.11646/phytotaxa.632.2.8.