Emergent palm bearing 10 or 11 leaves. Stem 6-19 m tall, 10-30 cm in diam. Leaf sheath 60-150 cm long, green with silvery indumentum; petiole 10-150 cm long; rachis 260-500 cm long; 44-46 pairs of segments, borne 4.9-7.8 cm apart, middle segment 60-85 cm long, 5-8 cm wide. Inflorescence 43-90 cm long; prophyll 42 or 43 cm long, 7 or 8 cm wide; peduncular bract ca. 39.5 cm long, ca. 5.5 cm wide; peduncle 10 16 cm long, 1.9-3.5 cm wide; rachillae 15-25 cm long, 1.8-2.9 mm in diam, brown lepidote, with 4-6 pistillate flowers per 5 cm. Staminate flower (bud before anthesis) 12.2-13.8 mm long, 6.5-8.4 mm in diam; sepals 4.0-5.9 mm long, 5.6-7.7 mm wide, densely brown lepidote on the abaxial surface; petals 10.2-11.9 mm long, 6.1-7.8 mm wide, brown lepidote on the abaxial surface; stamens 69-138, 6.8-10.0 mm long, creamy white; filaments 4.1-6.3 mm long; anthers 4.0-6.1 mm long, 0.6-0.8 mm wide, smooth; pistillode 7.9-11.8 mm long, 1.0-1.4 mm in diam at base. Pistillate flowers ca. 6.9 mm long, ca. 7.0 mm in diam; sepals ca. 4.1 mm long, ca. 5.0 mm wide; petals ca 4.3 mm long, ca. 3.4 mm wide; staminode not seen; pistil ca. 3.2 mm long, ca. 1.7 mm in widest diam. Fruit 39.4-49.2 mm long, 25.1 33.7 mm in diam; endocarp 39.1-39.7 mm long, 25.9 32.1mm in diam, endocarp wall 1.5-3.5 mm thick, brown with embedded black fibres; seed ca. 23.2 mm long, ca. 19.2 mm in diam.
Originaria, Papua New Guinea
Ptychococcus lepidotus is a palm of montane rainforest, at 760-1620 m in elevation. Ferrero (1996) gave 3000 m as the upper limit in elevation. Hay (1984) said that it was a common element of the lower montane rainforest dominated by Castanopsis (D. Don) Spach, in the vicinity of Bulolo. Its natural distribution corresponds to central Papua New Guinea, but it is widely cultivated and perhaps moved about by humans. The only known specimen from Indonesia was taken from a cultivated plant. It is not known to occur naturally in Indonesia.