Perennial, robust herb or undershrub; stem short, stout, covered by the thick leaf bases; leaves in lax rosette, stiff, sword-shaped or oblong-lanceolate, plicate, glaucous, with recurved tips, inner surface concave, colour dark green, sometimes greenish blue, reaching up to 60 cm long and 5-10 cm wide at their widest point, marginal teeth thin, subulate-conical, tip spinose; flowers greenish-yellow to white in terminal panicles, about 5 cm long clustered on very stout thick, scape; flowers bracteate, actinomorphic, numerous, yellowish-green, perianth lobes-6, elliptic-oblong, tube funnel shaped, segments oblong, spreading, margins inrolled; stamens-6, longer than perianth, anthers oblong or linear; ovary terete or fusiform, 3-celled, ovules many, style filiform, slender, stigma lobed; capsules oblong-clavate, many seeded.