Habit and leaf form. ‘Arborescent’ (arborescent). Leaves cauline. Plants with a basal concentration of leaves (more or less acaulescent), or with neither basal nor terminal concentrations of leaves; rhizomatous. Pachycaul. Mesophytic, or xerophytic. Leaves small to large; alternate (crowded at the top of the stem, a terminal rosette); spiral, or distichous; leathery, or modified into spines, or ‘herbaceous’; sessile; sheathing. Leaf sheaths not tubular; with free margins. Leaves simple. Leaf blades entire; solid; solid/angular (quadrangular); narrowly linear (gradually tapered to the apex); parallel-veined; without cross-venules; widely expanded with scarious margins, sheathing. Leaves without stipules. Leaf blade margins entire (scarious). Vegetative anatomy. Plants with silica bodies. Leaf anatomy. Hairs present (long, multicellular hairs present at leaf bases). Extra-floral nectaries absent. Stem anatomy. Secondary thickening absent.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in heads (derived from simple raceme or spike). Inflorescences scapiflorous, or not scapiflorous; terminal, or axillary (just below the stem apex, in the upper leaf axils, 1 inflorescence per axil); scape covered by bracts; peduncle stout and unbranched; inflorescences 4–100 per plant, globular or ovoid, many-flowered. Flowers pedicellate (almost sessile), or sessile; bracteate (scape bracts imbricate, herbaceous, silky-hairy, broad-sheathing base, extended apical point; floral bracts 1 per flower, broad herbaceous, silky hairy, persistent, acute); bracteolate (2 per flower, lateral, narrow keeled); small; regular; 3 merous; cyclic; pentacyclic. Perigone tube present, or absent. Hypogynous disk absent. Perianth of ‘tepals’; 6; 2 -whorled; isomerous; sepaloid to petaloid (glumaceous); glume-like, somewhat dry; similar in the two whorls, or different in the two whorls; white, or cream, or yellow, or hyaline; fleshy, or non-fleshy. Androecial members definite in number. Androecium 6. Androecial members free of the perianth, or adnate; all equal; free of one another; 2 -whorled. Androecium exclusively of fertile stamens. Stamens 6 (in 2 whorls); all more or less similar in shape; diplostemonous; attached to the receptacle, hypogynous or adhering to the base of the inner segments. Anthers basifixed; dehiscing via longitudinal slits; introrse; appendaged (shortly 2-lobed at the base). Pollen shed as single grains. Gynoecium 3 carpelled. The pistil 3 celled. Carpels isomerous with the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 3 locular; sessile. Gynoecium stylate. Styles 1; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1; 1 - lobed, or 3 - lobed. Placentation axile. Ovules 1 per locule; non-arillate; anatropous to campylotropous.
Fruit and seed features. Fruit non-fleshy; indehiscent; a capsule, or capsular-indehiscent; 1 seeded. Seeds endospermic. Embryo well differentiated. Testa without phytomelan.
Additional characters Pollen grains extended- sulcate.