Tuberous herb sprouting in early autumn from a rhizomatous tuber 7-10(-15) cm long, 1.5-3.5 cm thick. Petiole terete, 20-45 cm long, 5-12 mm wide, dark to mid-green, sometimes flushed with purple basally. Leaf-blade sagittate-hastate to oblong-sagittate, apex subacute to obtuse, 15-55 cm long, 10-32 cm wide, semi-glossy, dark green, lightly to moderately blotched moderately blotched with silver-grey above. INFLORESCENCE smelling strongly of stale urine. Peduncle much shorter than the leaves, terete, 5-14 cm long, 7-12 mm wide, pale to mid-green. Spathe 16-29 cm long; spathe-tube oblong-cylindic, 2-5 cm long, 1.5-2.5 cm wide, constricted apically, exterior pale to mid-green, paler basally, usually flushed with purple along the margin, interior pale greenish white below, mid-purple above ; spathe-limb lanceolate-elliptic to elliptic, 14.5-24 cm long, 7-15 cm wide, erect, apex acuminate, the tip soon drooping after opening, externally pale to mid-green, flushed with pale purple along the margins, especially towards the apex, internally greenish white with sccattered shiny, translucent patches, ± flushed with pale purple along the margins and at the apex, rarely the whole spathe is pale purple, or entirely pale green. Spadix more than ½ as long to just exceeding the spathe limb, 9-27 cm in total length; appendix massively conic-cylindric to stoutly clavate-cylindric, shortly stipitate, 7-23.5 cm long, 9-15 mm wide, dull ochre-yellow to pale creamy yellow, more rarely pale purplish cream or purple, stipe cream to yellow. Staminodes in 5-7 whorls; bristles filiform, flexuous, 6-7 mm long, pale yellow, stained with purple; bases conic, verrucate, pale yellow. Interstices : upper 1-2 mm long, longitudinally ridged, pale yellow, lower ± absent. Staminate flowers in an oblong zone, 5-7 mm long, 9-11 mm wide; anthers and connectives pale yellow, stained with purple apically. Pistillodes 2 whorls forming a zone 3-5 mm long; bristles filiform, flexuous, 3-4 mm long, pale yellow below, purple above; bases bulbiform, smooth, pale cream. Pistillate flowers in a cylindric cluster 9-15 mm long; ovaries ovoid-cylindric, 2.5-3 mm, pale green; stigma whitish grey. Fruiting spike oblong-pyriform, 6-7 cm long, 2-2.5 cm wide; berries oblong-pyriform, 4-14 mm long, 2.5-5 mm wide. Germination epigeal.