Notes on the nomenclature and taxonomy of Chiastophyllum and Umbilicus oppositifolius (≡ Cotyledon oppositifolia, ≡ Chiastophyllum oppositifolium) (Crassulaceae subfam. Sempervivoideae) Author Smith, Gideon F. 0000-0002-5417-9208 Ria Olivier Herbarium, Department of Botany, Nelson Mandela University, P. O. Box 77000, Gqeberha, 6031 South Africa. smithgideon 1 @ gmail. com; https: // orcid. org / 0000 - 0002 - 5417 - 9208 smithgideon1@gmail.com Author Monro, Anna M. Australian National Herbarium, Centre for Australian National Biodiversity Research (a joint venture between Parks Australia and CSIRO), GPO Box 1700, Canberra ACT 2601, Australia. text Phytotaxa 2022 2022-09-16 564 2 239 247 journal article 147237 10.11646/phytotaxa.564.2.7 0ac69fbc-2113-4f21-8b1f-e5a926eea567 1179-3163 7087286 Umbilicus Candolle (1801: 1) . Type :— non designatus fide Farr & Zijlstra (1996 +). Heterotypic synonyms :— Umbilicus sect. Chiastophyllum Ledebour (1843: 176) ; Chiastophyllum (Ledeb.) Stapf (1930: 176 , 316–317). Type :— Cotyledon oppositifolia Ledeb. ex Nordmann (1837: 313) ( Turland et al . 2018 : Art. 40.3). Name in Chiastophyllum : Chiastophyllum oppositifolium (Ledeb. ex Nordm.) Stapf (1930: 316–317) ; name in Umbilicus : Umbilicus oppositifolius (Ledeb. ex Nordm.) Ledebour (1843: 176) .