Terrestrial or hemiepiphytic; internodes on juvenile dark green, semiglossy, soon transversely fissured, becoming gray to brown, 3-8 cm long, 9-17 mm diam.; on adult, to 10 cm long, 3.5 cm diam., brown and coarsely fissured transversely; cataphylls green, tinged red with two sharp, low ridges, deciduous; petioles 26-43 cm long (averaging 34 cm), 4-7 mm diam. at middle, obtusely flattened laterally, sometimes conspicuously so, almost twice as wide as thick, medium green, weakly glossy, densely striate, often tinged maroon at apex; blades broadly ovate, acuminate at apex, cordate at base, 26-39 cm long, 21-34 cm wide (averaging 33.5 X 27 cm), 1.1-1.4 times longer than broad, 0.7-1.1 times length of the petioles, broadest near point of petiole attachment, subcoriaceous, moderately bicolorous, semiglossy; anterior lobe 22-28 cm long; posterior lobes 8-15 cm long, 10-17 cm wide, directed weakly inward; sinus spathulate, 5-13 cm deep, 3-6 cm wide; midrib flat and paler above, convex and dark maroon-purple below; basal veins 7-8 pairs, 3-4 pairs free to base; posterior rib naked only for first 1-2 cm; primary lateral veins 7-10 per side, departing midrib at 45°-75° angles, deeply sunken above, round-raised and dark maroon-purple below; minor veins few, moderately obscure; INFLORESCENCES 5 per axil; peduncle 2-3 cm long, 1-2 mm diam., pale green; spathe 3-4 cm long, 4-7 mm diam. (unopened); tube white inside, pale green outside; blade white inside, white, tinged greenish toward base outside; spadix 4.0-4.5 cm long; pistillate portion yellow-green, 1.5-1.7 cm long, 6-7 mm diam.; staminate portion pale orange (inner core bright orange in cross-section), 2.6-2.8 cm long, 8-9 mm diam. at base, 6-7 mm diam. at apex; sterile staminate portion indistinguishable from fertile staminate portion (on dried material); staminate flowers 1.1-2.0 mm long, 0.7-1.1 mm wide; pistils 1.4-1.8 mm long, 1.0-1.2 mm diam.; stigma 0.3-0.4 mm diam.; locules 5 per ovary; ovules 0.9-1.0 mm long, 1 per locule; placentation basal.
Philodendron aurantispadix is endemic to the type locality at La Planada at 1,700 to 1,850 m elevation in Premontane wet forest. It has been collected twice at La Planada, once along the trail to Pialapi, past the entrance to La Planada Field Station and once in a location not specifically known.