Perennial, stout shrub; stem short, woody, marked with scars of fallen leaves; leaves linear-lanceolate, thick, fleshy, densely crowded in rosette at base, striate, margins spinous, stiff, cuspidate, spines upcured, apical spine stout, sharp; flowers shortly pedicellate, pendulous, bisexual, actinomorphic, yellowish-green in large, terminal panicles on stout, branched scape; perianth shortly constricted above the ovary; tepals-6, greenish yellow or white, elliptic-oblong or oblanceolate; stemens 6, inserted at the base of tepals and adpressed to the stylar column, filaments flattened, dilated in the middle, anthers oblong, versatile; ovary 3-celled, ovules many, style thickened at base; fruit berry or capsule, trigonous or 3-valved, globose or elliptic-obovate; seeds numerous, flattened.