Herbs [shrubs], perennial, not viviparous, 0.3-6 dm, glabrous or pubescent. Stems erect [scandent], branching, succulent. Leaves persistent, cauline, opposite [alternate], petiolate [sessile], base (or petiole) often subclasping; petiole to 20 cm; blade elliptic, ovate, obovate, or oblong-spatulate, laminar, 3-20 cm, fleshy, base not spurred, margins entire, crenate-dentate, or lobed; veins not conspicuous. Inflorescences terminal [lateral] cymes, often paniculate. Pedicels present. Flowers erect, 4-merous; sepals connate basally, all alike; petals erect or spreading, connate into 4-gonal, flask-shaped tube, yellow, orange, or red; calyx and corolla not circumscissile in fruit; nectaries subquadrate to linear; stamens [4] usually 8; filaments adnate near top of corolla tube; pistils (connivent), erect, (nearly distinct); ovary base tapered; styles mostly 2+ times shorter than ovary. Fruits erect. Seeds ellipsoid, ribbed, finely cross-ribbed. x = 18.

Some species of Kalanchoe are grown as houseplants or as greenhouse plants, or in warm climates as rock-garden plants. Bryophyllum, often included, is treated here as a separate genus.