Philodendron tenue K.Koch & Augustin

Usually hemiepiphytic, rarely terrestrial or epilithic; stem usually appressed-climbing, thick, short, leaf scars inconspicuous; internodes striate, 2-3.5 cm long, 1-2.5 cm diam., about as long as broad, dark green to olive-green; roots drying tan to brownish red to blackish, smooth, elongate, 7 - 28 cm long, 0.2 - 0.5 cm diam., usually few per node, rarely numerous per node, dense, spreading at the nodes, epidermis peeling; cataphylls membranous, 28 - 31 cm long, 8 cm broad at base, usually unribbed, sometimes bluntly or sharply 1-ribbed to sharply 2-ribbed, green, red or purplish green, pale white-striate, drying brownish to reddish brown, persisting intact, eventually fibrous. LEAVES ± erect; petioles 29-107 cm long, 2-11 mm diam., erect, ± terete, stiff, firm, dark green, sometimes somewhat flattened with a low medial rib adaxially, surface weakly semiglossy, weakly light green striate with many small, fine ridges; geniculum thicker than petiole, 3 - 4 cm long, scurfy, slightly paler than petiole; blades ovate to ovate-triangular with prominent posterior lobes, chartaceous to subcoriaceous, moderately bicolorous, narrowly acuminate, sometimes long-acuminate at apex (the acumen inrolled, 1-4 mm long), cordate at base, 31-78 cm long, 16-52 cm wide (1.2-3.1 times longer than wide), (0.6 - 1.4 times longer than petiole), margins weakly undulate, upper surface gray-green to dark green, glossy, lower surface semiglossy, paler; anterior lobe 30.5 - 60 cm long, 14 - 34 cm wide (1.5 - 3.8 times longer than posterior lobes), broadest at point of petiole attachment; posterior lobes 10 - 29.5 cm long, 6 - 16.5 cm wide, broadest at or near the middle, directed downward and outward, sometimes inward, obtuse to sub-rounded to bluntly acute; sinus triangular, acute to almost obtuse, sometimes closed, 4.5 - 17 cm deep; midrib flat to sunken, concolorous to slightly paler than surface above, raised, concolorous, drying somewhat paler than surface below; basal veins 5 - 7 per side, with 0(1) free to base, part of the remainder coalesced 2 - 10.5 cm; posterior rib not naked; primary lateral veins (6)8 - 14(20) per side, departing midrib at a 65-90¡ angle, ± straight or weakly arcuate to the margins, prominently to narrowly sunken above, raised to convex below; inter-primary veins as conspicuous as primary lateral veins, weakly sunken and concolorous above, weakly raised and concolorous below; minor veins moderately visible to distinct below, arising from both the midrib and primary lateral veins. INFLORESCENCES erect, to 4 per axil; peduncle 2-11 cm long, 3 - 18 mm diam., pale green, drying reddish brown, heavily white-lineate, drying longitudinally fissured; spathe erect to erect-spreading, coriaceous, acuminate at apex, 7 - 14 cm long, (1.3 - 4.4 times longer than peduncle), moderately constricted above the tube, 2.1 cm diam. at constriction, short-lineate throughout; spathe blade weakly lanceolate, greenish white, sometimes heavily tinged red outside, 4 - 8 cm long, 2.1 cm diam., (opening 3.6 cm long), white to pale green inside; spathe tube ovoid, medium to dark green, usually tinged red or sometimes dark violet outside, white-striate with clear margins in front, short, pale green lineate in back outside, 3-7 cm long, 2-3.5 cm diam., white to pale green, sometimes red at base inside, sometimes sparsely white-spotted; spadix sessile; 6-12 cm long; pistillate portion yellowish green to pale green, weakly tapered upward, 2.8^4 cm long in front, 1.9 - 2.2 cm long in back, 1.1 - 1.6 cm diam. at middle, 1.75 cm wide at base, 0.9 - 1.5 cm ca. 1 cm from apex, with 12 - 14 flowers per spiral; staminate portion 5.3 - 7.1 cm long; fertile staminate portion white, drying orange reddish to light reddish, 1 - 1.1 cm diam. at base, 1.2 - 1.5 cm diam. at middle, 7 - 10 mm diam. ca. 1 cm from apex, broadest in the middle, as broad as to slightly broader than the pistillate portion, as broad as to narrower than the sterile portion, 27 - 35 flowers visible per spiral; sterile staminate portion as broad as to broader than the pistillate portion, pale brown, 11 - 17 mm diam.; pistils 2.7 - 3.1(6.2) mm long, 1.2-1.7(3.9) mm diam.; ovary 4 - 5-locular, 1.6-2(5.9) mm long, 1.2 - 1.7(3.9) mm diam., with axile placentation; locules 1.6-2(4.2-5.9) mm long, 0.4 - 0.7(1.1) mm diam.; ovules 12-14 per locule, 2-se-riate, 0.4 mm long, longer than funicle; funicle 0.2(0.5) mm long, adnate to lower part of partition, style 0.5 - 0.6 mm long, 1.2 - 1.7 mm diam., similar to style type B; style apex flat; stigma cupullate, ± hemispheroid, 1.1 mm diam., 0.4-0.6 mm high, covering center of or entire style apex, depressed medially with 6 - 8 holes; the androecium truncate, prismatic, margins irregularly 4 - 6-sided, (0.3)0.7 - 0.9 mm long, 1.1 - 1.4 mm diam. at apex; thecae oblong, 0.3-0.4 mm wide, ± parallel to one another, nearly contiguous; sterile staminate flowers irregularly 4-6-sided, mostly prismatic, sometimes clavate, blunt, 1.3 - 2.5 mm long, 1.4 - 2.5 mm wide. INFRUCTESCENCE with fruits purplish.