Usually hemiepiphytic, sometimes epiphytic or terrestrial; stem appressed-climbing, sometimes creeping, to 1 m long, sap clear, sticky, sometimes black pepper-scented, leaf scars conspicuous, to 2.5 cm long, to 1.5 cm wide; internodes semiglossy, sometimes becoming matte, sometimes scurfy, 1--4(11) cm long, 1.5--3.5 cm diam., usually longer than broad, dark green to grayish or grayish green to brown, epidermis thin, drying brownish, irregularly ridged, frequently transversed fissured, cracking off; roots olive-green to brownish, slender, 0.6--100 cm long, to 3 mm diam., semiglossy, somewhat twisting, drying pale; cataphylls to 34 cm long, bluntly to sharply 2-ribbed (ribs to 5 mm high), green, densely short, dark green lineate or speckled, sometimes persisting as a rotting mass, eventually deciduous. LEAVES erect-spreading to spreading to weakly arching; petioles 14--42 cm long, more or less terete, slightly spongy, medium green, obtusely flattened and sometimes with an obscure medial rib near apex adaxially, sometimes with adaxial margins erect, blunt, surface sparsely dark green short-lineate or unmarked, sometimes with a purple ring at apex, sheath 4--9.5 cm long; blades oblong to oblong-ovate, subcoriaceous, moderately bicolorous, semiglossy, subcordate at base, 24--73 cm long, 8--29 cm wide (2.5--3 times longer than wide), (ca. 1.7 times longer than petiole), margins moderately undulate, upper surface dark green, lower surface paler; anterior lobe 23.5--68 cm long, 11--27.5 cm wide, (10.5--15.6 times longer than posterior lobes); posterior lobes usually narrowly rounded and somewhat spreading or borader than long, rarely cordulate and about as long as broad, 1.5--6.5 cm long, 4.1--11.6 cm wide; sinus open or closed with lobes overlapping; midrib flat to broadly convex, slightly paler than surface or concolorous above, convex to bluntly acute, mostly concolorous, sometimes minutely speckled, matte or slightly semiglossy below; basal veins (1)2--3(4) per side, usually all free to base, sometimes with 2 united for up to 2 cm; posterior rib usually absent, never naked when present; primary lateral veins 6--10 per side, departing midrib at a 60--70º angle, more or less straight to the margins, obtusely sunken, paler than surface above, convex to weakly raised and darker than surface below; interprimary veins flat and darker than surface below; minor veins moderately distinct to more or less obsure above and below, arising from both the midrib and primary lateral veins. INFLORESCENCES erect to spreading, 1--2(3) per axil; peduncle 3.6--11.5(17) cm long, to 1.8 cm diam., somewhat flattened adaxially, green, sometimes tinged red, weakly lineate or unmarked; spathe 12.3--22 cm long, (1.7--3.4 times longer than peduncle), to 3 cm diam. (when closed), oblong-linear, acute at apex, weakly constricted above the tube; spathe blade white to greenish white outside (opening 8.5 cm long, 5.5 cm wide), pale green, with orange resin canals inside; spathe tube green outside, 5--7 cm long, 2.3 cm diam., green, reddish to maroon or maroon-streaked at base inside; spadix stipitate to 4 mm long; white, 9--14.7 cm long, broadest above the middle, weakly constricted above sterile staminate portion; pistillate portion pale green, cylindrical, 2.9--5.4 cm long, 0.9--1.3 mm diam., weakly narrowed toward both ends; staminate portion 6.8--12.5 cm long; fertile staminate portion white, cylindrical to clavate, weakly tapered at apex, (5--7)12--15 mm diam. at base, 8--16 mm diam. at middle, (4)6--9 mm diam. ca. 1 cm from apex, broadest at middle or at base; sterile staminate portion narrower or broader than pistillate portion, white, 4--15 mm diam.; pistils 1.5--2.1(3.5) mm long, ovary (5)7--8-locular, 0.8--1.2(2) mm diam., with sub-basal or basal (or axile placentation in Croat 69250); ovules 1--2(4-5) per locule, 1-seriate, contained within transparent ovule sac, 0.3--1.7 mm long, longer than or equal in length to funicle, style similar to style type B; style apex with the shallow depression completely covered by stigma; style boss sometimes shallow, broad; stigma discoid to button-like (brush-like), 0.5--1 mm diam., less than 0.3 mm high, drying with the crown button-shaped and flat to concave with moderately large stylar pores around its periphery; the androecium margins 5(4--6)-sided, somewhat scalloped, 2 mm long; thecae oblong, 0.5 mm wide, nearly contiguous, sometimes divaricate; sterile staminate flowers more or less rounded. INFRUCTESCENCE (immature), pale yellow-green outside; spadix to 3 cm wide, pistillate spadix 8--11 cm long; berries pale green to white; seeds tan, 1 mm long, 0.6 mm diam. JUVENILE petioles sheathed nearly throughout; blades oblong, obtuse to rounded at base, lower surface sometimes maroon.