Notes on the nomenclature and taxonomy of Chiastophyllum and Umbilicus oppositifolius (≡Cotyledon oppositifolia, ≡Chiastophyllum oppositifolium) (Crassulaceae subfam. Sempervivoideae)
. Phytotaxa [Internet]. 2022 Sep. 16 [cited 2025 Apr. 7];564(2):239-47. Available from: https://phytotaxa.mapress.com/pt/article/view/phytotaxa.564.2.7