A revision of the Malagasy Kalanchoe subg. Kitchingia (Crassulaceae subfam. Kalanchooideae): history, taxonomy, and nomenclature Author Smith, Gideon F. Department of Botany, Nelson Mandela University, P. O. Box 77000, Port Elizabeth, 6031 South Africa. Author Klein, David-Paul Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt University of Berlin, Albrecht-Thaer Weg 2, 14195 Berlin, Germany. Author Shtein, Ronen The Steinhardt Museum of Natural History, Tel Aviv University, Klausner St 12, Tel Aviv-Yafo, Israel. text Phytotaxa 2021 2021-06-04 507 1 67 80 http://dx.doi.org/10.11646/phytotaxa.507.1.3 journal article 10.11646/phytotaxa.507.1.3 1179-3163 5425523 Key to the taxa of Kalanchoe subg. Kitchingia 1a. Plants small, epiphytic; leaves basally cuneate; corolla colour variable (red through orange to pinkish orange to yellow or yellowish green), generally more intensely coloured than in Kalanchoe peltata ; stamens generally included ...........2 [ Kalanchoe gracilipes ] 1b. Plants robust, terrestrial; leaves basally peltate; corolla colour variable (red through pink to yellowish pink or yellowish green or whitish), generally less intensely coloured than in Kalanchoe gracilipes ; stamens generally exserted ...........3 [ Kalanchoe peltata ] 2a. Leaf blade 10–30 mm long; margins subentire to deeply crenate, typically 7- to many-toothed; stem up to 2.5 mm in diameter ..... ................................................................................................................................................... Kalanchoe gracilipes var. gracilipes 2b. Leaf blade 5–6 mm long; margins deeply crenate to lobed, typically 3-toothed; stem up to 1.5 mm in diameter .............................. ................................................................................................................................................ Kalanchoe gracilipes var. microphylla 3a. Stems robust, often ± 4-angled; petiole distinctly widened basally, comparatively short; blade often weakly peltate, strongly crenate, lack violet-black blotching pattern; calyx and corolla ± 4-angled; sepals acute .................... Kalanchoe peltata var. stapfii 3b. Stems flexuose, cylindrical; petiole slightly widened basally, relatively long; blade strongly peltate to peltate-cordate, crenations shallow and wide, adorned with violet-black blotches; calyx and corolla rounded; sepals obtuse ...................................................4 4a. Leaves covered ad- and abaxially with simple, obtuse-tipped hairs; blade often cordate-deltoid ....................................................... .................................................................................................................................................. Kalanchoe peltata var. mandrakensis 4b. Leaves glabrous; blade ovate ............................................................................................................... Kalanchoe peltata var. peltata