B.1 Kalanchoe subg. Kalanchoe, automatically established in 1919 when K. subg. Bryophyllum was published (see next) (Turland et al. 2018: Articles 6.8, 22.1, and 22.3) (Fig. 5).

Type:—As for the genus.

Description:—Perennial, short-lived multiannual, or biennial, terrestrial or epiphytic, large or small succulent shrubs or shrublets. Roots fibrous or more rarely substantially thickened, plants sprouting from roots very uncommon. Stems ± herbaceous, often weak, sometimes robust. Leaves variously shaped, not bulbiliferous. Inflorescence not bulbiliferous post-flowering, i.e., they are not flori-bulbiliferous. Flowers usually erect or spreading-erect at anthesis, brightly or dull-coloured; calyx tube usually very short, inconspicuous, often tightly clasping the corolla tube lower down or more rarely diverging from corolla tube; corolla generally flimsy, rarely somewhat succulent; corolla tube not obscured by the minimal calyx tube; corolla tube usually gradually narrowing towards mouth, sometimes constricted ± above the carpels, often yielding narrowly tapering, urn-shaped appearance; stamens ± inserted in upper ½ of corolla tube, often in ± two ranks; filaments often short, of two similar or slightly dissimilar lengths, often near mouth; anthers inserted, then distinctly visible at the mouth, or ± exserted; carpels often as long as styles; nectar scales variously shaped, generally ranging from thin, ribbon-like-linear to large, cuneiform-quadrangular, then apically somewhat 3- lobed. Chromosome number (basic): x = 17.

Kalanchoe subg. Kalanchoe has a very wide natural geographical distribution range that covers the whole of the area of occurrence of the genus (see ‘Introduction’, above). Several species are globally popular in landscaping, gardening, and floriculture (Smith & Shtein 2021a, Smith 2024b).

Morphologically, representatives of K. subg. Kalanchoe are very variable, but they are never arborescent.