STEM: erect, 50 (-100) cm tall, 5-15 cm diam., decumbent, or rhizo-matous, subterranean and appearing acaulous at soil surface, usually forming extensive stands; adventitious roots present, c. 0.8 cm diam.; internodes less than 1 mm long; prophyll scars less than 1 mm long; intravaginal squamules frequent to numerous, not long-persistent, 3-5 mm long, 1-2.5 mm wide at base, triangular-lanceolate, usually flattened; foliage leaf scars transverse-elliptic, c. 1 cm long, 2.3 cm wide. LEAF: prophyll 20-40 cm long; petiole (32-)40-90 (-104) cm long, usually distinctly longer than blade, 0.6-1 cm diam. at apex, above flattened to broadly sulcate with rounded margins; leaf blade normally broadly sagittate, somewhat glaucous, margins normally weakly repand, rarely subentire or sinuately lobed, overall length 30-52(-56) cm, overall width (21.5-)24-42(-44) cm; anterior division 20-37 cm long, 21-42 cm wide, normally wider than long, widest at base, apex subacute to rounded and apiculate, primary lateral veins 3-5 per side, concentrated towards segment base, arising at angle of (30-)40-90° to midrib; posterior divisions 10-20 cm long, 0.3-0.4 x overall blade length, 12-22(-25) cm wide, basal ribs denuded for 1.5-3 cm, tip normally retrorse, more rarely introrse or extrorse, acute-acuminate to broadly rounded, primary acroscopic veins 1-3, primary basiscopic veins 0-5, often very weak when present, width of basiscopic lamina very variable. INFLORESCENCE: peduncle (16-)20-46(-55) cm long, 1 -2 cm diam. at apex, spathe tapering towards apex, (9-)12-20 cm long, (2-)2.5-4(-4.3) cm diam. at middle, decurrent for (2.5-)3-4.5 cm, pale green on outer surface, cream-white on inner surface; spadix 12-17.5 cm long, fertile male zone (3.5-)4 - 5.5(-6.8) cm long, 1.1-1.8 cm diam., ± cylindric, narrower than sterile male zone, sterile male zone (4-)5.7-10 (-11) cm long, slightly conical, tapering from 1.6-2.4 cm diam. at base to 1.3-1.8 cm diam. at apex, female zone 1.3 - 2.5(-2.7) cm long, 1-2( -2.3) cm diam. FLOWERS: stamens 2.7-4 mm long, (0.6-)0.7 - 1(-1.3) mm diam. at apex; staminodes (1.3-)2-5 mm long, 1-1.8 mm diam. at apex, clavate, usually tapering evenly towards the base, occasionally more abruptly swollen at apex; gynoecium 3-4.5 mm long, ovary a little narrower than stigma, ± cylindric, raphide cells common to abundant in subepidermal tissue of ovary walls from apex to base, locules 4-8, ovules (1-2) per locule, inserted near base and at middle of ovary, well spaced from one another, style body slightly narrower than style crown and ovary, densely packed with abundant raphide cells around stylar canals, compitum not penetrating ovary, style crown with tanniniferous style lobes, central dome usually lacking, occasionally present and then equalling style lobes in height, stylar canals entering locules subapically, stigma (1.5-)1.8 - 2(-2.7) mm wide, containing many tannin hairs. INFRUCTESCENCE: No fertile fruit seen.