Moderate to large, solitary or clustered, hapaxanthic, monoecious palms. Stems with ± elongate internodes, obscured at first by persistent fibrous leaf bases and sheaths, usually becoming bare, conspicuously ringed with narrow leaf scars, striate. Leaves induplicately bipinnate (except in juveniles where pinnate), marcescent or abscising under their own weight; sheath triangular, eroding opposite the petiole into a mass of strong black fibres, a ligule-like extension frequently present, disintegrating into strong black fibres, the sheath surface covered in a dense felt of indumentum and caducous chocolate-brown scales, sometimes in broad stripes; petiole scarcely to well developed, channelled adaxially, rounded abaxially, bearing indumentum like the sheath; secondary rachises similar in form to the primary rachis, arranged ± regularly except rarely in 1 or 2 species where the most proximal few crowded; leaflets very numerous, borne ± regularly along the secondary rachises, obliquely wedge-shaped with no distinct midrib but several major veins diverging from the swollen, sometimes stalk-like base, upper margins deeply praemorse, blade concolorous, with broad bands of caducous chocolate-brown scales abaxially, transverse veinlets obscure. Inflorescences bisexual, solitary, produced in a basipetal sequence, interfoliar and sometimes infrafoliar (the proximal few), usually branched to 1 order, rarely to 2 orders (Caryota ophiopellis) or 3 orders (C. zebrina) or rarely spicate (C. monostachya), usually pendulous; peduncle ± circular in cross-section, densely scaly; prophyll tubular at first, soon splitting, 2-keeled, relatively small, densely tomentose and/or scaly; peduncular bracts to ca. 8, conspicuous, large, enclosing the inflorescence in bud, coriaceous, tubular at first, tending to split irregularly, usually densely tomentose and/or scaly; rachis shorter or longer than the peduncle; rachillae spirally arranged, densely crowded, usually scaly, each subtended by a small, low, triangular bract; the rachilla base usually somewhat swollen, with a short to moderately long bare section above this, distal portion of rachilla bearing close or rather distant, spirally arranged, protandrous triads, each subtended by an inconspicuous rachilla bract; floral bracteoles shallow, rounded. Staminate flowers usually ± elongate, symmetrical; sepals 3, ± distinct, coriaceous, ± rounded, imbricate; petals 3, valvate, coriaceous, connate at the very base, considerably exceeding the sepals; stamens 6–ca. 100, the filaments short, basally sometimes connate, anthers ± linear, latrorse, the connective sometimes prolonged into a point; pistillode absent. Pollen ellipsoidal, ± bi-symmetric; aperture a distal sulcus; ectexine intectate, usually finely and densely clavate, less frequently spiny, spines attached to smooth upper surface of foot layer, in some species spines more numerous along aperture margin, or gemmate, occasionally with gemmae linked together to form incomplete reticulum, or coalesced into larger irregular units; longest axis ranging from 26–31 µm; post-meiotic tetrads usually tetrahedral, sometimes tetragonal or, rarely, rhomboidal [8/14]. Pistillate flower ± globular or elongate; sepals 3, coriaceous, rounded, imbricate, connate at the very base; petals 3, coriaceous, valvate, connate into a tube in the basal ca. 1/3–1/2; staminodes 0–6; ovary rounded or somewhat 3-angled, trilocular with 1–2 locules fertile, septal glands present basally, stigma trilobed, apical, ovule hemianatropous, inserted adaxially at the base. Fruit globose, 1–2-seeded, with apical stigmatic remains; epicarp smooth, becoming dull, bright or dark coloured at maturity, mesocarp fleshy, filled with abundant, irritant, needle-like crystals, endocarp not differentiated. Seeds basally attached, irregularly spherical or hemispherical, somewhat grooved or smooth, endosperm homogeneous or ruminate; embryo lateral. Germination remote-tubular; eophyll bifid with rhombic, divergent, praemorse segments. Cytology: 2n = 34.
All species appear to be utilised in some way. The apex is edible and good. Stems provide sago, the larger species being especially favoured. Timber of Caryota urens is used for construction purposes. Leaf sheath fibres are extremely durable and harvested for thatch, cordage, and other purposes. The woolly indumentum on leaf sheaths, petioles, and rachis is used variously as tinder or wadding. Inflorescences, especially of C. urens, are tapped for palm wine or sugar. There are several other minor local uses. Many species are cultivated as ornamentals.