Usually terrestrial and deeply rooted, rarely epiphytic, 30-100 cm tall; stem short, 2-2.5 cm diam., internodes short; leaf scars to 2.5 cm wide, cataphylls drying brown, persisting intact.

LEAVES erect-spreading; petioles 14-50 cm long, 5-9 mm wide, 3-sided, sharply winged (or the abaxial side sharply 2-ribbed) the wings sometimes wavy; geniculum 1.5-2 cm long; blades ovate to broadly ovate, subcoriaceous, gradually to abruptly short-acuminate at apex, deeply lobed at base, (13-)20-40(-55) cm long, (13.5-) 15-35 (-40) cm wide, broadest at middle or just below. the upper surface semiglossy, the lower surface much paler, matte or semiglossy; midrib obtusely raised above, diminishing and sunken at apex, sharply raised below, basal veins 4-6(-7) pairs, up to 4 of them coalesced 1-2.5 cm, raised in valleys on upper surface; the posterior rib more or less straight, naked or not; primary lateral veins 6-10 per side, departing the midrib at 30-50° angle, straight then arcuate-ascending to the collective vein, weakly raised in valleys above. prominent below; interprimary veins few. prominulous above; collective veins arising from one of the basal veins, loop-connected, mostly 3-17 mm from margin.

INFLORESCENCE erect, shorter than leaves; peduncle 14÷30 cm long, 5-8 mm diam., subterete, sharply 1(-2)-ribbed abaxially below middle, spathe light green to yellowish green, streaked dark green or purple, oblong-lanceolate, (3-) 10-14 cm long, (1-)2-3 cm wide, broadest ca. 1 cm above the peduncle. gradually acuminate at apex (the acumen hooked). rounded to obtuse at base, spreading to reflexed. inserted at ca. 45° angle on peduncle; spadix sessile, green, (2.6-)5-14.5 cm long, (4-)6-12 mm diam. near base, with a strong perfume-like scent when stigmas have droplets and when anthers arc fresh; flowers rhombic or weakly 4-lobed, 3.1-3.8 mm long, 2.8-3.5 mm wide, the edges nearly straight on sides paralleling the flower spirals, usually jaggedly sigmoid at alternate edge. sometimes jaggedly sigmoid on both sides. 8 flowers visible in the principal spiral, ca. 5 flowers visible in the alternate spiral; tepals glossy. smooth, sometimes with minute droplets: the inner margin more or less straight; pistils darker green than tepals, glossy; stigma oblong, ca. 0.6 mm long; stamens emerging more or less rapidly from the base or scattered throughout spadix, weakly exserted above the tepals, soon retracting. withdrawing most of the anther beneath the tepals, the pollen deposited at edge oftepal, anthers ephemeral, 0.3-0.6 mm long, 0.6-0.8 mm wide. thecae oblong-ellipsoid, scarcely or not divaricate, pollen orange.

INFRUCTESCENCE spreading; berries violet purple at apex, white at base, obovoid, ca. 6.5 mm long. 5 mm diam.: seeds 1 or 2, 4-4.3 mm long, 2.7-3.7 mm wide, 1.7-2.4 mm thick, pale brown, emarginate at apex, rounded to obtuse at base. Figs. 17, 18, and 21.

The species is known only from the vicinity of the Isthmus of Panama in premontane wet and tropical wet forest life zones at 500 to 1,000 m. It is most abundant west of the Canal Zone.

The species is a member of section Cardiolonchium and is apparently not closely related to any other known species in the section. It can be recognized by its cordate blade, its sharply three-sided winged petiole, its terrestrial habit, its green to golden yellow spadix that exudes pollen in ribbons, and by its violet purple berries.

Map of Mesoamerican specimens with coordinates

Panama CoclŽ: 900-1000 m, 08.39N 80.36W, 31 March 1993, Thomas B. Croat 75059 (MO).
Panama CoclŽ: 800 m, 08.39N 80.36W, 31 March 1993, Thomas B. Croat 75083 (MO).
Panama CoclŽ: 800-900 m, 8.38N 80.09W, 11 July 1987, Croat 67162 (F, MO).
Panama CoclŽ: 710-800 m, 89.39N 80.36W, 22 June 1988, Thomas B. Croat 68761 (MO).
Panama CoclŽ: 89.39N 80.36W, 23 June 1988, Thomas B. Croat 68811 (MO).
Panama CoclŽ: 850 m, 8.39N 80.36W, 13 09 1987, Croat 67580 (MO).
Panama CoclŽ: 800 m, 08.36N 80.07W, 6 July 1994, Thomas B. Croat & Guanghua Zhu 76663 (MO).
Panama CoclŽ: 770 m, 08.38N 80.35W, 12 July 1994, Thomas B. Croat & Guanghua Zhu 76770 (MO).
Panama CoclŽ: El Valle de Antón Region, 775 m, 8.36N 80.07W, 25 Mar. 1993, Thomas B. Croat 74785 (CM, MO, SCZ).
Panama Panamá: 800 m, 08.41N 79.56W, 23 March 1993, Thomas B. Croat 74769 (MO).
Panama Panamá: 460 m, 09.19N 79.59W, 3 April 1993, Thomas B. Croat 75105 (MO).