Robust herb to 1 m high; rhizome ovoid or cylindrical, yellow-orange, getting bluish in upper part with a smell of old potatoes, 6.4-11.0 x 3.9-6.6 cm; sap copious; tunic to 8 cm, usually large, matted and fibrous, rather easily detached, brown-red. Outer leaves 3 to 5, ovate, dull maroon-brown at the base, 6-14 x 0.8-1.4 cm, ciliate on the margins and midrib below, glabrous above; trichomes tufted, white; nerves of unequal size, (29 to) 39 to 67; inner leaves 8 to 27, linear, grass green except whitish basal parts, (12-) 21-48 (-66) x 0.6-1.6 cm wide, in basal part wider and with membranous margins, prominently keeled, ciliate on the margins and midrib below, glabrous above; trichomes tufted, adpressed, ca. 4-branched with branches 0.5-2.7 mm long, white or grey; thin nerves of equal size, very densely arranged (when dry), (29 to) 33 to 67. Scapes 3 to 13, 13-27 cm x 3-4 (-5) mm, basally tapering, shortly winged and ciliate, in upper half prominently hispid with tufted trichomes; raceme 6- to 12-flowered, floral anthesis acropetal; bracts subulate, lowermost 11-25 x 1.5-2.0 mm, 7-nerved, pubescent on midrib and nerves abaxially; upper bracts much smaller, almost filiform; pedicels 4-23 mm long, hispid. Tepals 6, clear yellow inside, green outside with pale yellow margins; outer tepals oval, 9-16 x 3-5 mm, 5- to 9-nerved with irregular nerves, abaxially hispid; appendage clavate; inner tepals ovate, obtuse, 9-14 x 4.5-10.0 mm, 5- to 7- (10-) nerved with irregular nerves, pubescent abaxially along the midrib; stamens subequal or inner shorter than outer, greenish yellow; outer stamens 5-9 mm long with filaments 3.5-4.5 mm long; inner stamens 4.5-7.5 mm long with filaments 2.5-3.5 mm long; anthers linear, prominently sagittate, slightly emarginate or fused at apex, 3.5-5.0 mm long; ovary 4.5-13.0 x 3.5-6.0 mm, hispid; style 1-2 mm long; stigma pyramidal, greenish yellow, 1.5-3.0 mm long. Capsule obconical, 6-10 x 4-5 mm, hispid; seeds 6 to 9, ovoid, 1.2-1.5 x ca. 1 mm, black and glossy; seed coat colliculate.