Tuber “large, flattened” (Barter), “as large as a child's head” (Johnson), “as large as a Cheshire cheese” (Irving). Leaves 5 ft. high (Johnson), “18 in. high, finely cut” (Barter); petiole smooth; segments 3–10 in. long, 2 1/2–7 lin. broad, linear or linear-lanceolate, tapering to a fine point, decurrent. Peduncle 2/3–2 ft. long, green suffused with purple, and spotted with blackish-purple, smooth. Spathe 7–13 in. or more long, 3–8 in. diam., convolute for half its length, cylindric or campanulate at the base, then dilating into an ovoid cucullate upper part, with an oblique ovate mouth in front, glabrous within and without, dull purple, striped with darker purple and spotted with whitish, or light green mottled with brown on the outside, shading into a bluish-flesh tint or whitish at the base, inside rich dark velvety-purple in the upper part, and striped with white and purple-red in the tube. Spadix not exceeding the convolute part of the spathe, stipitate; stipes 1/3– 1/2 in. long, cylindric; flowering part dense, female 1/3– 3/4 in. long, cylindric, male 1–1 3/4 in. long, stout, obconic; appendix 2–4 in. long, 1–3 1/2 in. thick, ovoid, obtuse, blackish-purple or yellowish-green, rugose. Ovary ovoid, 1-celled, green; style 1–1 1/3 lin. long, jointed near the middle; stigma small, discoid or cushion-like. Anthers very crowded, pale brownish-green.