Plants 3–6 m tall. Rhizome composed of subglobose tubers, to 6 cm diameter. Leaves: sheaths more or less lanuginose; lamina narrowly to broadly ovate-elliptic, 35–120 by 20–45 cm, base rounded, apex obtuse to acute, sometimes shortly acuminate, lower side more or less lanuginose. Inflorescence generally unbranched, flowers solitary, sessile; primary bracts 11–39 cm long, obtuse, sometimes mucronate; branch bracts 4–18 cm long, acute; floral bracts broadly ovate to broadly elliptic, 1.8–4.1 cm long, obtuse, persistent; bracteoles ovate-triangular, 2.3–4 cm long, obtuse; rhachis, bracts, bracteoles, and sepals glaucous. Flowers greenish white, yellowish white, or purplish white, erect, 9–13 cm long; floral tube slightly curved around the middle, resulting in a horizontally orientated entrance to the flower; sepals whitish green, narrowly elliptic to narrowly ovate, 2.2–4.5 by 0.6–1.6 cm, obtuse or acute; corolla purplish, 7–12.5 cm long, petals reflexed, narrowly triangular, 6–10.5 by 1–2 cm, acute; staminodes 4, (greenish) white or yellowish, 9–13 cm long, free part narrowly obovate, 4–6 by 1–2 cm, apically more or less patent; stamen greenish yellow to whitish, free part narrowly obovate-elliptic, 3–5 by 1–1.7 cm, theca 2–4 cm long; style yellowish green, free part linear to narrowly elliptic, 3.5–5.5 by 0.5–0.8 cm. Fruit maturing brown, narrowly ellipsoid to ovoid, 5–10.5 by 2.5–5 cm. Seeds subglobose to broadly ellipsoid, 8–10 by 6–7 mm.