Emergent palm bearing 6-13 leaves. Stem 6-26 m tall, 9-25 cm in diam. Leaf sheath 63-150 cm long, green with silvery indumentum; petiole 0-33 cm long; rachis 250-470 cm long; 32-95 pairs of segments, borne 4.3-8.2 cm apart, middle segment 33-102 cm long, 3 12 cm wide. Inflorescence 50-150 cm long; prophyll 32-47 cm long, 4-15 cm wide; peduncular bract 33-58 cm long, ca. 7 cm wide; peduncle 8-19 cm long, 2-10 cm wide; rachillae 9-28 cm long, 1.3-4.3 mm in diam, glabrous, with 3-8 pistillate flowers per 5 cm. Staminate flower (bud before anthesis) 11.2-16.8 mm long, 5.4-9.6 mm in diam; sepals 3.6-6.8 mm long, 5.2-6.9 mm wide; petals 9.8-15.9 mm long, 4.2-8.4 mm wide; stamens 100-213, 4.7-13.1 mm long; filaments 1.9-10.7 mm long; anthers 2.0-6.5 mm long, 0.3-0.8 mm wide, bullate; pistillode 6.7-15.9 mm long, 0.7-2.9 mm in diam at base. Pistillate flowers ca. 7.6 mm long, ca. 8.8 mm in diam; sepals 4.2-5.4 mm long, 5.2-7.5 mm wide; petals 4.0-6.0 mm long, 2.6-5.5 mm wide; staminode ca. 1.2 mm long; pistil 2.5-6.3 mm long, 1.1-4.1 mm in widest diam. Fruit 39.2-59.8 mm long, 21.6 45.0 mm in diam; endocarp 31.0-55.4 mm long, 20.4 33.1 mm in diam, endocarp wall 0.5-1.2 mm thick, black; seed 20.9-28.1 mm long, 15.2-24.9 mm in diam..
へのネイティブ, Papua New Guinea, Indonesia
Ptychococcus paradoxus is a palm of lowland rainforest or alluvial forest, often over limestone, at 0-850 m in elevation. The palm often grows in very wet or swampy habitats, sometimes in association with Metroxylon sagu, or along riverbanks or in flood plains. It is widespread throughout lowland New Guinea, although much of its present range may be due to distribution and cultivation by humans.