Perennial herb 10–68(72) cm tall from a ± fleshy tuber-like base; plants solitary not clustered, rosulate (erect), glabrous with leaves ciliolate. Tubers 1–3.5 cm in diameter, ± subglobose to flattened and disc-like in mature plants, with numerous radiating fleshy tapering roots. Stems absent. Leaves 3 to numerous, in a dense rosette, arching becoming ± prostrate, glabrous with ciliolate margins, sheathing at the base; the bases successively overlapping bases of inner leaves, persisting as scarious hyaline sheaths which usually break down into numerous long fibres through the centre of which the new leaves and peduncle emerge; blade thickly fleshy, 5–42 cm long and 1–6.5(9) cm wide toward the base, ovate or broadly to narrowly lanceolate, tapering to the apex. Peduncles 1–5 per plant, stout, erect, 7–40 cm long, ± strongly flattened in the lower part and up to c. 7(12) mm wide with narrowly hyaline ± ciliolate wings. Raceme usually densely many-flowered, sometimes ± laxly-flowered, (3)5–20(35) cm long, narrowly cylindrical; bracts membranous, 4–12 mm long, narrowly lanceolate and ± finely tapering to the apex, sometimes ciliolate on the margins, exauriculate, persistent; pedicels mostly erect to ascending, filiform or slender, c. 3–11(16) mm long, straight, persistent. Tepals bright yellow, up to c. 6.5 mm long, the inner c. 3 mm wide, the outer 1.5–2 mm wide, elliptic, persistent. Filaments c. 4–5 mm long, all densely bearded about the middle with long very narrowly linear hairs; anthers c. 1 mm long. Style 3–5 mm long, terete. Capsule not inflated when mature, c. 2.5–3.5(5) mm long and 3–3.5(4) mm wide, obovoid, shallowly 3-lobed. Seeds 1–3 per locule, c. 2–3 mm long, pyramidal, narrowly winged on the angles, convex on the outer face with 2–3 flat inner faces tapering to the point of attachment, black, sometimes with a reticulate pattern of low incipient ridges on the surface.