Climbing herb. Stem 1-2 cm diam., internodes 1-4 cm long, in upper part with semi-intact, dry cataphylls persistent and slowly weathering to shreds and fibers. LEAVES: Petiole somewhat spongy, weakly flattened adaxially, to 48 cm long (equaling or slightly exceeding blade). Leaf blade subcoriaceous, ovate, to 42 cm long, 25 cm wide at point just below petiole insertion, apex briefly acuminate, posterior lobes more or less trapeziform and separated by a narrowly parabolic sinus to 12 cm deep. INFLORESCENCE unknown.
The retention of the old cataphylls easily distinguishes this species from P. acutatum. Also, the nervature is inconspicuous, drying darker brown than the ground color of the blade, and' the primary lateral veins arise at a sharper angle. In P. acutatum, the veins are conspicuous, drying much paler than the base color of the blade, and the primary lateral veins originate at a wide angle (70-80°). From P. ornatum Schott, this taxon differs by the petiole weakly flattened adaxially and the leaf blade of different outline.