Tuber hemispherical, 5–15 cm diam., 4–8 cm thick, flat or slightly sunken above, rounded and whitish to brownish below, 5–20 cm below ground level. Tubercles few, rounded, 0.8–1 cm diam., borne around the periphery of tuber. Roots 2.5–3 mm diam. Cataphylls 1–3, 6–22 cm long, 1.5–3 cm wide, pinkish or light brown, reaching or surpassing ground level. Leaf solitary. Petiole 1–2.5 m long above ground, 2.5–4 cm diam. at mid-point, dark green or medium green tinged brown, contrastingly mottled with dirty-white or pale green blotches and forming a reptilian pattern, smooth or sometimes with spiny projections. Juvenile blade sagittate, or sagittately lobed. Adult blade spreading horizontally, 1–1.4 m diam., subcoriaceous, sometimes fenestrate, never variegated, without raphide cells or dark markings, semiglossy and dark green above, matte and medium green below; middle division twice trichotomously branched, 50–65 cm long, 50–60 cm wide, with terminal subdivision consisting of three sections, with each basal subdivision consisting of many segments; lateral divisions twice dichotomously branched, 47–60 cm long, 45–55 cm wide, with terminal subdivision consisting of two sections, with basal subdivision consisting of many segments; terminal and subterminal sections not confluent, each usually consisting of a single segment or each consisting of a few segments; broadly oblanceolate, more than 5 cm wide on each side of the major ribs, ovate-oblong or elliptic or lanceolate, mostly not confluent with each other in each division, without contrastingly smaller rounded or triangular segments (often); apices acuminate, or acute (rarely); ultimate segments 20–32 cm long, not confluent with penultimate segments; other segments 9–20 cm long; penultimate segments not confluent with the subterminal sections; medial segments not confluent with the basal subdivisions (often); basal segments present, free from each other; rachises patterned distinct from petiole, pale green, smooth; tertiary veins prominent above and weakly raised below. Bracteoles 1–4, 4–24 cm long, 1.5–3 cm wide, light brown, the longest one much shorter than the peduncle, confined at the base of the peduncle. Inflorescence solitary, appearing before or after new leaf. Peduncle (56–)100–145 cm long above ground, 1–2.5 cm diam. at mid-point, more than half as long as the petiole or sometimes as long as or longer than the petiole (sometimes), mottled similar to petiole but deeper in color, dark green, smooth in upper half or with irregular protuberances in lower half or spiny projections. Spathe 30–45 cm long, 4–6 cm wide, non-cymbiform, constricted at a certain point and differentiated into a proximal tube and a distal lamina (blade), non-cucullate, erect or slightly arching, apex acuminate; 8–12 cm long, 4–6 cm wide at widest point; lamina 3–5 times longer than the tube; inner surface covered with dense, translucent scales 1–2 mm long, olive-brown or reddish purple, with translucent area obvious, 8–15 cm high, 1.5–3 times longer than spadix; outer surface green or green tinged brown, matte; margins entire, broadly overlapping at the base; veins obscure inside and raised outside, similar to the spathe in color. Spadix hidden, stipitate, cylindric, brown or purple or dark purple, 3.5–6 cm long, 0.7–1 cm diam. at anthesis, never with appendages at apex; stipe 0.5–1 cm long, 0.5–0.8 cm diam. at anthesis, light brown. Flower tepals (4-)5–6(-7), 0.5–2.5 mm long, 1–2 mm wide, purple or dark purple. Stamens 5–7; filaments 0.3–2 mm long; anthers 0.3–0.5 mm long, hidden or slightly exserted. Ovary 3-locular, pale green or whitish; stigma unlobed; style 0.5–1.5 mm long above tepals, purple or greenish, persistent. Infructescence with spadix 8–16 cm long, 2–4 cm diam. in fruit. Berries 0.7–0.8 cm diam., 0.7–1 cm thick, obliquely obovoid, apically rounded or subtruncate; young berry medium green; mature berry orange, without reddish dots and raphide cells. Seeds 1-seeded or 2-seeded, 0.6–0.8 cm diam., rounded, reddish brown, laterally flattened; dorsal ridges obvious, 3, strongly interrupted (often), with the central ridge contrastingly raised, more than 1 mm thick, 0.1–0.2 mm high, warty along ridges.

Type: Peru. Loreto: Province Maynas, Pebas on Río Ampiyacu, 3°10'S, 71°49'W, Plowman et al. 6729 (holotype, F [1825130]; isotypes, F, GH).

Napo: Parque Nacional Yasuní, Pozo Petrolero Conoco﷓Amo 2, 0°57'S, 76°13'W, 230 m, Neill 8160 (CM, MO, QCNE);.