Cotyledon, Linnaeus, 1753

Crouch, Neil R. & Smith, Gideon F., 2023, Cotyledon mckayi (Crassulaceae subfam. Kalanchooideae), a new cremnophytic species from the central Tugela River Basin of KwaZulu-Natal, South Africa, Phytotaxa 632 (2), pp. 184-192 : 190-191

Identification key to distinguish among representatives of Cotyledon documented from KwaZulu-Natal

1. Corolla tube bulging about the middle; tube always at least 18 mm long .............................................. C. orbiculata var. oblonga

1’ Corolla tube not bulging about the middle; tube shorter than, or not longer than, 18 mm .............................................................. 2

2. Corolla tube base bulging prominently between the calyx lobes ..................................................................................... C. barbeyi

2’ Corolla tube base not bulging between the calyx lobes, or very slightly so .................................................................................... 3

3. Filaments lacking a tuft of hairs at their point of insertion in the corolla; found from Mzimkulu River valley southwards ............. ........................................................................................................................................................................................... C. velutina

3’ Filaments with tufted hairs at their point of insertion in the corolla; found from Umkomaas River valley northwards ................. 4

4. Leaves and flowers puberulous, lacking waxy bloom; leaves petiolate; leaf blade ovate to elliptic .................................. C. nielsii

4’ Leaves and flowers glabrous, with waxy bloom; leaves sessile; leaf blade linear-lanceolate, elongate-obovate, or narrowly cymbiform .......................................................................................................................................................................... C. mckayi