Monoecious tree, 4-5 m tall; trunk at first decumbent, the upright part to 2 m high, 30 cm or more thick, bearing old leaf bases; crown usually broader than tree height. Leaves broadly spreading, the tips of the lower leaves often touching the ground; petioles 1-2 m long, 9-12 cm broad near base, broadly canaliculate, the sharp edges bearing spinelike teeth; rachis roughened on underside with brown scales; blades 2-4 m long; leaflets regular, in 60-110 pairs, to ca 1 m long, 4-6 cm wide, the apex oblique, the midrib prominent on upper surface with 2 faint marginal ribs on lower surface. Inflorescences borne among leaf axils; spathes thin, obscure, soon becoming a mass of dilacerating fibers, the outer spathes to 30 cm long, the inner to 50 cm long in staminate flowers, to 60 cm long in pistillate; staminate inflorescences soon weathering, the peduncles 20-35 cm long, ca 1 cm thick, the rachillae numerous, 20-25 cm long, ca 1 cm thick; stamens 6, the filaments partly united into a staminal tube ca 3 mm long; pistillate inflorescences 30-40 cm long, the peduncles ca 40 cm long, the rachillae stout, irregular, 4-9 cm long, closely compacted, pointed at apex; flowers white, sunken in rachillae, subtended by 2 or 3 bracts; tepals 6, ca 8 mm long; staminodial rings 6-dentate, ca 2 mm high; styles white, exserted and receptive for about a day, then becoming black; fruiting inflorescences usually broader than high, to 30 cm wide. Fruits orange, of irregular shapes due to mutual pressure, 2-3.5 cm long, often with persistent styles; seeds 1-3. Croat 5203, 5539. Common only at the margin of the lake, but seen also in the seasonally swampy area near Standley Trail 500 and below the escarpment south of Armour Trail 700. Seasonal behavior uncertain. Flowers have been seen only during the early rainy season, but since flowers last for such a short time with the old inflorescences persisting, it cannot be said that flowering does not occur over a longer period of time. The fruits are present all year on some individuals, but most mature during the late dry or early rainy seasons. Individuals may bear more than one fruiting inflorescence in different stages, indicating the possibility that the plant flowers more than once a year. Standley's plate VI in the Flora of Barro Colorado Island (1933), labeled Corozo oleifera, isScheelea zonensis. Bailey (1943) reported that fruits are black at maturity. My observations indicate that the fruits become loose and fall while still orange. However, fruits that are not able to fall free do become black. Central America to Colombia and the Guianas (perhaps only introduced into northern South America). In Panama, a characteristic element of premontane wet forest (Tosi,1971); known also from tropical moist forest on BCI and in Darién. Collected from tropical wet forest in Costa Rica (Holdridge et al., 1971).