Appressed-climbing hemiepiphyte; internodes I- 3 cm long, 1.7 cm diam., drying initially blackish and smooth, becoming minutely, finely and irregularly ridged, matte, finally light yellow-brown and smooth with big folds, sometimes with the epidermis loosening; cataphylls 8 cm long, sharply 1-ribbed on drying, drying blackened, deciduous. LEAVES: Leaf blades oblong, 41.5-43 X 6-6.7 cm, 6.9 times longer than wide, 2-2.3 times longer than petioles, narrowly acute at base, narrowly caudate-acuminate at apex, semiglossy, slightly bicolored, drying medium gray-green above, slightly paler and yellowish gray-green below; midrib broadly convex and slightly darker than surface above, narrowly convex and darker than surface below, drying finely and inconspicuously ridged on both surfaces; primary lateral veins not at all apparent; minor veins numerous, fine, arising at 35°-45° angle, sometimes drying weakly undulate. INFLORESCENCES 2 per axil; peduncle 4-6 cm long, drying black, 3 mm diam. midway; spathe 8.5-9.5 cm long, drying 1.2-1-5 cm diam.; stipe 4 mm long in front, 5 mm wide; spadix 8.7 cm long, ca. 0.8 mm shorter than the spathe; pistillate portion of spadix 2.1 cm long, drying 7X3 mm wide; staminate portion of spadix 6.5 cm long, drying 5X8 mm wide. Pistils 0.8-1.0 mm long; 5- to 6-locular; stigmas 0.6-0.8 mm diam.; ovules 1 per locule, basal 0.6-0.7 mm long; enveloped in a gelatinous envelope 2 mm long; fu-nicle ca. 2 times as long as ovule.
It is characterized by its somewhat grayish drying, narrowly oblong-oblanceolate blades that lack any obvious primary lateral veins and its moderately small, narrowly pedunculate, blackish drying inflorescences. It is closest to P. paxianum K. Krause, which differs in having leaf blades with distinct primary lateral veins.