Philodendron tuerckheimii Grayum

Much-branched rigidly scandent vine climbing on trunks or in understory vegetation to 6 (-10?) m above ground with elongate, ligneous climbing stems and dark wiry, spreading-pendent branches; occasionally flowering on appressed-climbing shoots (e.g., Mori & Kallunki 2869). Internodes 0.1-13.1 cm long, 0.3-0.7 (-1.0) cm wide (-2.5 cm on larger stems?) dark or olive-green to gray-green, dark brownish purplish green, purplish gray or blackish green, virtually matte to (more usually) semiglossy, narrowly flattened or sulcate on one side drying cafe-an-lait to chocolate-brown or blackish rather coarsely and sharply sulcate; roots rare at distal nodes and few when present (rarely abundant) to ca. 1.5 mm in diameter. LEAVES: Petiole (2.7-) 3.5-7.9 (-12.6) cm long, P/L= (0.29-) 0.34-0.53 (-0.74), semiglossy, extensively sheathed, the sheath broadly horizontally spreading or rarely erect-spreading, sometimes resolute the free portion prolonged (sometimes asymmetrically) by 0.05-0.50 (-0.80) cm (frequently beyond base of lamina); unsheathed portion of petiole obsolete to ca. 0.4 (-0.8) cm long. Lamina (6.5-) 7.9-17.8 (-21.2) cm long, (2.5-) 3.2-8.0 (-12.1) cm wide, L/W=(1.49-) 1.77-4.03 (-4.55), IQI=(0-) 1-7 (-8), membranous to subcoriaceous, matte (occasionally somewhat glaucescent) to glossy above, matte to semiglossy below, virtually concolorous to moderately bicolored, broadly lanceolate or narrowly ovate to ovate, deltate, oblong, narrowly elliptical or (rarely) slightly oblanceolate (broadest at or, most commonly, below the middle, rarely slightly above), abruptly to ± gradually and somewhat falcately acuminate apically [the acumen ca. 0.6-1.9 (-2.6) cm long], cuneate to (more usually) rounded, subpandurate, cordulate (with the sinus to ca. 0.25 cm deep) or somewhat truncate basally; midrib narrowly sulcate above, convex below (may be slightly paler than surface); primary lateral veins 5-8 (-10) per side, 0.1-2.8 (-3.5) cm apart, weakly sunken above, weakly convex below; minor veins visible though not prominent below, slightly darker; abaxial laminar surface drying virtually smooth to obscurely or (rarely) moderately to densely granular (the granules often concentrated along the major veins), with the reticulate veins evident only distally; white stitching not evident or scattered to abundant; resin canals obscure to (more usually) long and very distinct, flanking the tertiary veins; adaxial surface similar, but virtually smooth to subalveolate or (most commonly) sparingly to densely granular, especially along the primary veins, and resin canals not evident, or only apically or in occasional interrupted streaks (or rarely long and distinct). INFLORESCENCES solitary; cataphylls absent; peduncle (0.8-) 1.0-2.6 (-2.8) cm long, P/S=(0.10-) 0.14-0.26 (-0.40?), often hidden by the sheaths of subtending leaves; spathe at anthesis 7.6-13.6 (-15.7) cm long, 1.2-2.8 cm wide, externally semiglossy, cream- to greenish white or yellowish green to light or medium green ("rojo-cremosa," Cuadros V. 2646), paler toward margins, internally pale green to whitish, somewhat constricted over intermediate sterile region; spathe drying smooth or obscurely roughened to very finely striate or moderately granular externally, sometimes with white stitching (may be abundant), the resin canals ± visible at some stages, internally virtually smooth or uniformly and obscurely to densely granular, with longitudinal secretory striations (1/2-) 2/3-5/6 (-9/10) to apex; acumen of spathe 0.1-1.1 cm long. Stipe of spadix (0.2-) 0.4-1.2 (-1.7) cm long; spadix (6.1-) 7.0-11.7 (-13.9) cm long, the fertile male portion (0.4-) 0.6-0.9 cm wide, white or creamy white ("spadix orangish distally," McPherson et al. 13491; "infls. anaranjadas," Dumont & Idrobo 164); sterile male zone, when evident, 0.15-0.60 cm long, yellowish (Croat 70725); fertile female portion of spadix 1.6-4.3 (-4.9) cm long (to 7.4+ cm in fruit), F/S—(0.23—) 0.31-0.42 (-0.49), 0.50-1.15 (-1.25) cm wide (to 2.0+ cm in fruit), light green; fertile male flowers 0.7-1.7 mm long, 0.6-1.6 (-2.3) mm wide, irregularly polygonal, columnar to anvil-shaped; sterile male flowers 1.2-1.8 (-2.5) mm long, 0.6-2.0 mm wide, columnar to obpyramidal or anvil-shaped; female flowers 1.1-2.2 mm long, 0.4-1.2 mm wide, the stylar canals (1?-) 2-4 (-5). INFRUCTESCENCES: Absolutely ripe fruits not described. Seeds 0.8-0.9 mm long, 0.25-0.30 mm wide (Grayum et al. 10573), straight to slightly curved, finely striate with the striae minutely cancellate, drying light brown and semiglossy.