Solitary palm. Up to 35 metres in height, with petioles up to 6 m long, the large leaves form a rounded crown. Fruit is a chestnut colour and is covered with shiny scales. The yellow flesh covers a hard, oval, nut. The seeds float, and this is the means by which the palm tree propagates. In natural populations the tree reaches very high densities.

Root: subterranean root branches into small, thin, absorbing roots; aerial roots have pneumatophores for oxygen uptake; can also produce many 2-10 em long erect aerial rootlets on stem ("aerial root muff"). Stem: 15-30 m tall typically 0.3-0.6 m in diam. but reported up to 1.75 m; cortex is hard, unarmed and straight with distinct internodes; middle of stem is sometimes swollen; pith is spongy, reddish in color and contains up to 60% dry weight in starch (up to 60 kg starch can be extracted); sap can be fermented to produce a wine; rotten stems (particularly male plants) inhabited by the edible Rhyncophorus sp. (Bruchidae) larva (up to 500 larvae/stem). Leaf: 10-12 per palm and restricted to a terminal crown; production 5-12 leaves/palm/ year; briefly costapalmate, approx. 3.0 m in diam. with deeply cut and glossy green blades 0.8-1.2 m long and 1.5-2.0 m wide; leaf-blades bear a low hastula-like crest ("shaped) adaxially at base and have prominent midribs; leaf-blades are 2-4 cm wide drooping at tips; last 2-3 years as thatch. Petioles 2-3 m long and conspicuously adaxially channeled near base; otherwise circular in cross-section, smooth and unarmed. Flower: dioecious, but occasionally hermaphroditic; interfoliar (originates among leaves), persistent and pendulous; 2-3 m long with numerous short, tubular bracts, and catkin-like branches; male flower has six stamens; young inflorescence produces a sap that can be fermented into wine. Pollination: known pollen transporter is Melipona seminigra merrillae (Apidae). Fruit: 5-8 fruiting panicles per tree with up to 724 fruits per panicle; productivity 6.19.1 mt fruit/ha/yr. Fruit is large, usually one-seeded and sometimes wider than long: 4 cm in diam. and up to 5 em long with depression at top; loricate pericarp: many neat vertical rows of reflexed scales, red-brown when mature; rather thick, fleshy, edible, yellowish-red mesocarp; spongy, undifferentiated endocarp; corneous, homogeneous endosperm. Average fruit weight 75 g; mesocarp represents 20.5% and endocarp 12.0% of fresh weight; moisture constitutes 67%. Mesocarp contains up to 12.0% oil, woody seed and kernel up to 4.8% oil, dry remainder of meso- and endocarp; 5.2% protein, 26.2% fat, 38.2% starch and sugar, 2.9% ash, 27.5% cellulose, 30-300 mg/100 g edible portion b-carotene (50,000-500,000 ill provitamin A), and 18.4 mg/100 g edible portion a-tocopherol (vitamin E). Seeds are used as vegetable ivory; nuts are baked, ground and consumed as abortifacent. (TED L. GRAGSON 1995)