Philodendron steyermarkii G.S.Bunting

Herb, long-scandent, up to 15 m long adhering to tree trunks, roots pendent. Stem tough, dark green, blended with purple near the apex, internodes 8-12 cm long and 1-1.5 cm thick. Cataphyll 9-9.5 cm long, pale green blended with purple soon pink to purplish, then marcescent, intense brownish and persistent in position. LEAVES: Petiole firm, sub-terete, slightly flattened ventrally, 13-24.5 cm long and 0,3-0,5 cm thick, pale green, blended purple upwards or pale wine-coloured in the distal 2 cm. Leaf blade thinly sub-coriaceous, barely brittle, smooth, oblong-elliptic or narrowly obovate, sub-cordate at the base (emarginate), apex obtuse with recurved acumen, 21.5-33 cm long and 7.5-10.5 cm wide, undulate on both sides of the midrib, in a series of ca. 14 regular concave depressions, the shapes itself not reaching as far as the margin, the margin itself sub-flat although revolute; adaxially glossy, bright ('laete') green, midrib moderately convex, 0.4 cm wide, 5-6 primary lateral veins on both sides, patent, barely distinguishable; abaxially rather glossy, pale green (almost silver-green), midrib angular, ivory-white, occasionally suffused with pink, and marked near the base with few elliptic wine-coloured spots. INFLORESCENCES solitary on pendent branches. Peduncle coloured in the same way as the petiole, pink at the apex, 6-6.5 cm long. Spathe (post anthesis and unopened) narrowly conical, narrowed towards the base, ca. 9 cm long, 1.6 cm wide below, not constricted between the tube and the blade; externally green or greenish-white and pink margined, marked below with 4 pink longitudinal stripes; internally cherry red-wine-coloured in the lower half, greenish above. Spadix somewhat shorter than the spathe, ca. 7 cm long; female zone 3.6 cm long and 1.3 cm wide. Pistillate flowers: ovary 2-locular, many ovules in each locule, superposed.