Solitary or very rarely clustered, moderate, pleonanthic, monoecioustree palms. Stems erect, conspicuously ringed with leaf scars, bearingan open cone of stout, usually densely prickly, stilt roots. Leaves ratherfew, pinnate, neatly abcising; sheaths tubular forming a well-definedcrownshaft; petiole short, adaxially channelled or flattened, abaxiallyrounded, bearing a variety of indumentum types; rachis adaxiallyangled, abaxially rounded; leaflets regularly arranged, asymmetricallydeltoid to elliptic, proximal margin entire for much of its length, distalmargin entire ca. 1/3 its length, otherwise praemorse, main ribsnumerous, radiating from the base, leaflet remaining entire or splittinglongitudinally between the ribs into narrow segments displayed indifferent planes giving the leaf a plumose appearance. Inflorescences solitary, infrafoliar, somewhat dorsiventrally compressed and erect inbud, branching to 1 order, branches pendulous when exposed,protogynous; peduncle well developed, elliptic in cross-section,winged at base; prophyll inserted near the base, short, tubular, 2-keeled, apically open, thinly coriaceous; peduncular bracts ca. 5,tubular, tips pointed, central ones larger than proximal or distal, ±flattened, eventually deciduous after anthesis; rachis ± flattened,shorter or longer than the peduncle, bearing spirally arranged,pendulous rachillae, each subtended by a minute collar-like bract;rachillae rather robust, often somewhat flattened, elongate, bearingspirally arranged, crowded triads; rachilla bracts and bracteoles scarcelyevident; staminate and pistillate flowers maturing at the same time.Staminate flowers open in bud, sepals 3, triangular, united basally in alow, complete or partially interrupted ring; petals 3, distinct, fleshy, markedly asymmetrical, lightly imbricate basally, much longer than the sepals; stamens 17–145, filaments very short, awl-shaped above expanded bases, anthers erect, basifixed, linear, acute or apiculate, latrorse; pistillode much shorter than the stamens, conical, briefly trifid. Pollen ellipsoidal, ± bi-symmetric; aperture a distal sulcus; ectexine intectate, upper surface of foot layer covered by fine, dense gemmae or clavae, loosely supporting short, wide-spaced, broad-based spines; longest axis 43–50 µm [2/5]. Pistillate flowers symmetrical, much smaller than the staminate, ± 3-angled; sepals 3, rounded, strongly imbricate, dorsally thickened; petals 3, distinct, strongly imbricate, ± rounded with a minute, triangular valvate apex; staminodes 6, minute, tooth-like; gynoecium obovoid, tricarpellate, triovulate, stigmas 3, apical, fleshy, reflexed, ovules basally attached, orthotropous, one usually larger than the others. Fruit separated at maturity, ellipsoidal to subglobose with eccentrically apical stigmatic remains; epicarp minutely roughened when dry, at maturity splitting into ± distinct valves at apex, exposing the rather dry white mesocarp with included reddish sclerosomes and slender fibres, endocarp thin. Seed ± ovoid, basally attached, hilum circular, raphe branches conspicuous, numerous, sparsely anastomosing, endosperm homogeneous; embryo eccentrically apical. Germination adjacent-ligular; eophyll bifid with praemorse tips. Cytology: 2n = 36.
Moderate solitary (very rarely clustered) pinnate-leaved tree palms ofhumid rain forest in Central and South America, the stems with an opencone of stilt roots; leaflets are rhomboid praemorse, sometimeslongitudinally divided to give the whole leaf an ostrich-featherappearance; fruit has apical stigmatic remains and embryo.