Sp. Pl. 1: 319. 1753.
Gen. Pl. ed. 5, 150. 1754.
Plants succulent, shrubby or arborescent, scapose. Stems erect, clambering or ascending, branched or not. Leaves succulent, crowded, often rosulate or distichous; blade margins spiny-toothed or entire. Inflorescences axillary or terminal, paniculate to more often racemose, dense, bracteate. Flowers usually nodding; perianth red to yellow; tepals connate basally to almost entirely into tube; stamens 3 or 6; style slender; pedicel not articulate. Capsules papery to woody. x = 7.
Introduced; primarily s and tropical Africa, also Madagascar, Arabian peninsula, and Atlantic islands (Madeira, Canary, and Cape Verde), naturalized in the Mediterranean region, India, and China.
Species 300 or more (2 in the flora).
Aloe saponaria (Aiton) Haworth, distinguished by its yellow sap and glaucous red flowers with yellow throats, is cultivated in the southwestern United States and has been observed to escape. Apparently it persists only when supplementary water is available.