Amorphophallus hayi Hett.

Rhizome horizontal, brown and green, to ca. 25 × 5cm, branching infrequently, internodes 1–1.3cm, leaf scars transversely oval; offset tubers long lasting, depressed, broadly attached; roots mainly developed from ventral side. Leaves solitary or paired or simultaneous with inflorescence, latter emerging from petiole sheath; petiole moderately glossy, background color dirty grayish green but nearly totally hidden by large, oval, confluent, reddish brown spots, 40–60 × 1–1.5cm, turgid, glabrous; leaf blade 50–70 cm in diam., anterior segment less strongly developed than posterior ones; rachises short, unwinged except for distalmost parts; leaflets paler green abaxially, moderately glossy green adaxially, lanceolate, 8–32 × 2.5–7cm, margin crispate-undulate, apex acuminate; venation quite strongly impressed. Inflorescence solitary or with leaf, long pedunculate; peduncle reddish brown to yellowish brown, densely covered with dark reddish brown, narrowly oval, often confluent spots, ca. 50cm, ca. 1.5cm in diam. at base, ca. 0.8cm in diam. at apex, glabrous. Spathe erect, basally loosely convolute, apical 1/3 horizontally spreading, outside base very pale purplish brown on a ± cream-colored background, with numerous small and slightly larger, punctiform, rounded, partly confluent, dark purplish brown spots, distally outside dirty cream colored with less numerous rounded spots but numerous tiny ones, to margin flushed with gray, inside base dark maroon, distally ± cream-colored with few tiny dark purple spots, to margin flushed with dirty dark brownish green, ovate, funnel shaped, margin involute, base and limb not differentiated, 16–20 × 12–15cm, base within with very shallow, interconnected ridges, apex narrowly acute. Spadix emitting a strong cheesy smell, shortly stipitate, longer than spathe, 20–28cm; female zone cylindric or slightly obconic, 1.8–2.2 × 1–1.3cm, distal limit irregular, flowers congested; ovary bright pale green with tiny reddish purple dots near stigma, very broadly ovoid, 2–2.3 × ca. 2mm, rounded in cross section, 1-loculed, ovule on a heavy placenta, running on one side to apex of ovary; style absent; stigma acroscopic on ovary, pale dirty yellowish, ± reniform, ca. 1 × 0.8mm, very thin, scaberulose; male zone fusiform or fusiform-obconic, 2–3 × 1.2–1.5cm, proximal and/or distal limit irregular, flowers congested; stipe ca. 2mm; appendix 16–23cm, basal part 1–1.7cm in diam., distal part ca. 4mm in diam., narrowly fusiform, upper half tail-like and horizontal, flexed or nearly erect, apex obtuse, all ± cream colored with a faint bright greenish hue, base with flattened staminodes separated by shallow grooves, distally diminishing, remainder glabrous; male flowers consisting of ca. 4 stamens; stamens 1.5–1.8mm; filaments whitish, ca. 0.3mm, basally connate; anthers dark pink to purplish, 1.2–1.5 × ca. 1mm, truncate, pores elongate, apical; pollen irregular, in tetrads, psilate to verrucate.