A review and analysis of the nomenclature and taxonomy of the genus-rank synonyms of Kalanchoe (Crassulaceae subfam. Kalanchooideae) published between 1763 and 1956

The genus name Kalanchoe, which is in use for about 200 tetramerous-flowered infrageneric taxa, species, and infraspecific taxa of Crassulaceae subfam. Kalanchooideae that are indigenous to Madagascar, some Indian Ocean islands off the African east coast, most of sub-Saharan Africa, and the Near, Middle, and Far East, was validly published in 1763 by Michel Adanson (1727–1806) and is legitimate. Genus names that are included in the synonymy of Kalanchoe are assessed and assigned to the appropriate subgenera recognised in the genus, and their nomenclature is reviewed. In chronological sequence the genus names in question are: (1) Vereia (1798), (2) Physocalycium (1820), (3) Baumgartenia (1821), (4) Meristostylus (1861), and (5) Geaya (1908); and (6) Bryophyllum (1805) is the basionym of K. subg. Bryophyllum (1919), and (7) Kitchingia (1881) is the basionym of K. subg. Kitchingia (2018). When Bryophyllum is treated as a synonym of Kalanchoe—a view followed here—the nothogenus name (8) ×Bryokalanchoe (1956) is a synonym of Kalanchoe.