Stout succulent or fibrous perennials. Stem present, or lacking. Leaves crowded in rosettes, large, usually stiff and ± fleshy, leaf-tip ending in sharp spine, margins often toothed. Inflorescence a large raceme or much-branched panicle on a long scape. Flowers bisexual, greenish or brownish. Perianth-segments ± equal, usually green, ± connate into tube, persistent. Stamens 6. Ovary inferior, 3-locular; style filiform; stigma slightly 3-lobed; ovules many in each locule. Capsule loculicidal. Seeds many, thin, flat. Spp. c . 300, of southern N. America and tropical S. America. Adventive sp. 1.