Monocarpic but perennating by stolons. Leaves fleshy and tough, in basal rosettes, with broad sheathing bases, 100-200 x 15-25 cm, ± glaucous, spinose-dentate, with stout blackish terminal spine 2-3 cm. Scape 4-7 m, becoming woody. Inflorescence narrowly pyramidal; bracts leafy, triangular; flowers densely clustered at ends of horizontal branches. Perianth segments linear, 2-2.5 cm, greenish-yellow; apices obtuse, white-villous or pubescent. Filaments 6-8 cm, glabrous; anthers 2.5-3 cm. Capsule ovoid-cylindrical, trigonous, 3.5-4 cm, woody. Fl. 7-8.
Cultivated as an ornamental, sometimes as a hedge plant, naturalised in the south.