Trees, shrubs, and succulents, perennial, simple to sparsely branched, rhizomatous, some tuberous-thickened. Leaves simple, alternate, usually crowded at bases of stems or ends of branches, sessile; blade fleshy, margins often prickly, venation parallel. Inflorescences terminal, axillary, or lateral, spicate, racemose, or paniculate. Flowers 3-merous, short- to long-pedicellate, rarely sessile; perianth red, brown, yellow, orange, or whitish; tepals petaloid, connivent or connate basally to almost entirely into tube, sometimes fleshy; stamens sometimes 3, usually 6, exserted or included; anthers dorsifixed, dehiscence antrorse; pollen grains monosulcate; ovary 3-carpellate, placentation axile, usually with septal nectaries; style terminal; stigmas punctate, discoid, or 3-lobed. Fruits capsular, rarely baccate, dehiscence loculicidal, apical. Seeds usually winged or flattened. Aloaceae are closely related to and included by some authors in Liliaceae. The juice of some Aloe species is used to make a purgative called bitter aloe; active ingredients include aloin and other anthraquinones. Additionally, the thick, mucilaginous gel of some species is widely used to treat minor thermal burns, itching, and sunburn.