Perennial herbs, subshrubs or shrubs. Lvs alternate, opposite or verticillate, free, simple and entire, toothed, or pinnatifid to pinnate, often with pseudobulbs or plantlets on margins, not crowded into dense terminal rosettes but borne along stems. Infl. of cymes usually arranged in thyrses, sometimes corymbose, generally with many fls, usually terminal. Fls 4-merous, ± pendulous. Calyx usually divided to much < 1/2 way, sometimes divided to c. ⅚; lobes equal. Petals united to form a tube > lobes, somewhat fleshy, greenish or purplish red; tube broadly cylindric to urceolate, 4-angled; lobes spreading or reflexed. Stamens 8, in 2 equal or unequal whorls, epipetalous, ± exserted. Scales free, linear to quadrate or semiannular. Carpels 4, ± connate at base. Seeds numerous.

Herbs, usually biennial or perennial, sometimes annual, sometimes subshrubs or small shrubs. Lvs usually opposite and decussate, free or connate at base, simple, entire, toothed or rarely pinnatifid, not crowded in terminal rosettes. Infl. a corymbose, paniculate or thyrsoid cyme, usually terminal with many fls. Fls 4-merous, ± erect. Calyx divided from c. 1/2 way to almost the base; lobes equal. Petals somewhat fleshy, forming a tube > lobes; lobes free, erect to reflexed, white, yellow to deep red, or sometimes purplish; tube rather narrowly cylindric, 4-angled. Stamens 8, in 2 unequal whorls, epipetalous, usually included. Scales free, very variable in shape. Carpels 4, slightly connate at base. Seeds numerous.