Amorphophallus

Description¹ Perennial herbs with subterranean, naked tubers. Tubers often depressed globose and large at maturity. Leaves solitary, or several as a result of leaf growth on accessory tubers; petiole cylindrical, solid, usually blotched or flamed, smooth to rough; blade tripartite, each of the 3 segments multifid with decurrent, erect to spreading leaflets (side lobes) which vary greatly in number; just like the tuber, the appertaining leaf becomes larger every year until an inflorescence is formed. Inflorescence solitary on the tuber, partly enveloped by a well-developed spathe; peduncle cylindrical, solid, usually blotched or flamed, smooth to rough; spathe seemingly funnel-shaped, tubular or campanulate, but on one side free and with overlapping margins, variously coloured and marked, withering and often falling off after anthesis; spadix female in lower part, becoming male in the upper part via a transitional zone, with a well-developed asexual part (appendix) at the top; flowers unisexual, lacking a perianth; female flowers with 1—4-celled ovary, style more or less absent to well-developed, stigma entire or lobed; male flowers with 1—6 stamens; anthers subsessile and 2-celled, dehiscent by an apical pore; male part and appendix of spadix fall off after anthesis, after which the female part elongates greatly. Fruit a 1—3-seeded, subglobose or elongated berry, usually red or orange, the upper ones maturing first.|— Amorphophallus konjac: tuber up to 30 cm in diameter and 20 cm long, weighing up to 10 kg, brown, seasonally producing numerous rhizomatous offsets; petiole up to 100 cm 8 cm, smooth or with scattered punctiform warts at the base, dirty whitish-pinkish with large dark green spots and smaller white dots; blade up to 2 m in diameter, highly dissected, rachises narrowly winged; leaflets elliptical, 3—10 cm 2—6 cm; peduncle up to 110 cm 5 cm; spathe 10—60 cm 10—55 cm, limb erect, undulate or folded longitudinally with spreading margins, outside dark purplish-brown with scattered blackish-green spots, inside dark brown, glossy; spadix 15—110 cm long; fruit unknown.|— Amorphophallus muelleri: tuber up to 28 cm in diameter, weighing up to 3 kg, dark brown outside, yellow inside, developing no seasonal offsets; petiole 40—180 cm 1—5 cm, smooth, green to brownish-green with numerous pale green spots; blade 75—200 cm in diameter, very dissected, carrying epiphyllar bulbils on the major ramifications; leaflets lanceolate, 10—35 cm 4—9 cm; peduncle 30—60 cm 0.5—3 cm; spathe 7.5—27 cm 6—27 cm, limb semi-erect or spreading, brownish-purple or greyish-green outside, inside purplish or brownish with greenish or brownish spots; spadix longer than spathe, 8—30 cm long; berry cylindrical to ovoid, 12—18 mm long, bright red, up to 1000 per infructescence, 2—3-seeded.|— Amorphophallus paeoniifolius: tuber up to 30 cm in diameter and 20 cm long, weighing up to 25 kg, dark brown, producing seasonal rhizomatous offsets up to 10 cm 4 cm; petiole up to 200 cm 20 cm, shallowly corrugate to strongly echinate-verrucate, pale to dark green with numerous pale blotches and small dark dots; blade up to 3 m in diameter, highly dissected, rachises winged; leaflets rounded-ovate to lanceolate, 3—35 cm 2—12 cm; peduncle 3—20 cm 1—8 cm, elongating to 1 m length in fruiting; spathe 10—40 cm 15—60 cm, limb spreading and strongly undulating, pale green to dark brown with paler spots outside, inside glossy dark brown; spadix shorter or longer than spathe, 7—70 cm long; berry cylindrical, 1.5—2 cm 8—10 mm, bright red.|— Amorphophallus variabilis: tuber up to 15 cm in diameter and 8 cm long, weighing up to 1.5 kg, white, producing seasonal rhizomatous, spindle-shaped offsets 1—1.5 cm long; sometimes 2 leaves are produced; petiole up to 120 cm 3.5 cm, smooth, pure green or variegated green-brown-green; blade up to 125 cm in diameter, rachises narrowly winged; leaflets elliptical to lanceolate, 4—34 cm 2—12 cm; peduncle 8—120 cm 0.4—3 cm; spathe 6—23 cm 5—20 cm, limb strongly reflexed at margin, green with black dots outside, creamy white to pale green or brown inside; spadix usually much longer than spathe, 9—58 cm long; berry orange-red, 1—3-seeded.