Robust, solitary, unarmed, pleonanthic, monoecious, tree palm. Stem erect, eventually becoming bare and ringed with leaf scars. Leaves massive, pinnate, apparently marcescent; sheath tubular at first, with a large, lateral obtuse lobe on each side, disintegrating into a mass of grey fibres; petiole absent; rachis adaxially channelled near the base, abaxially rounded, distally with 2 lateral grooves; leaflets single-fold, very numerous, ± regularly arranged, more slender and crowded at the base of the rachis than distally, ± rigid, acute, adaxially glabrous, abaxially covered with a thin layer of powdery white wax, transverse veinlets short, conspicuous. Inflorescences solitary, interfoliar, exserted from leaf sheaths, branching to 1(–2) orders; peduncle massive, elliptic in cross-section, densely grey-tomentose; prophyll inserted at the base of and ± equalling the peduncle in length, thick, coriaceous, persistent, disintegrating into coarse interwoven fibres, strongly 2-keeled, tubular, splitting briefly at the tip; peduncular bract inserted at the apex of the peduncle, ± the same length as the prophyll, thin to extremely thick (up to 3 cm), woody, tubular, with a solid beak, splitting or not, but circumscissile at the insertion, caducous, leaving a collar-like scar, adaxially smooth, shiny, abaxially tomentose and longitudinally shallowly grooved; rachis very short, bearing crowded, spirally arranged, short, triangular, acuminate, coriaceous bracts each subtending a first-order branch, the proximal few sometimes bearing 1–2 second-order branches; rachillae straight, rigid, rather thick, each with a large swelling at the very base, forming a spherical pulvinus, proximally with a very short bare portion, distally bearing subdistichous or strictly distichous flower groups, each subtended by a low triangular bract, the rachilla surface sparsely waxy or bare, flowers borne in triads throughout much of the rachilla length except near the tips where flowers solitary or paired and staminate, or near the base where flowers occasionally in tetrads of 2 pistillate and 2 staminate; floral bracteoles well developed, broad, rounded, striate, rather coriaceous. Staminate flowers relatively very large, covered with white wax (?always), subsymmetrical; sepals 3, distinct, keeled, imbricate, coriaceous, rather short; petals 3, distinct except at the very base, valvate, strongly coriaceous to woody, ± boat-shaped, much longer than the sepals, somewhat striate, adnate at the very base to the floral axis; stamens 15–21, filaments short, slender at the base, adnate to the floral axis, anthers elongate, erect, ± basifixed, sometimes irregularly sagittate; pistillode absent or minute (Beccari and Pichi-Sermolli 1955). Pollen ellipsoidal, usually with either slight or obvious asymmetry; aperture a distal sulcus; ectexine tectate, finely perforate, perforate and micro-channelled, or perforate-rugulate, aperture margin slightly finer; infratectum columellate; longest axis 43–52 µm [1/1]. Pistillate flowers only slightly larger than the staminate, covered in thin wax (?always); sepals 3, distinct, broadly imbricate, hooded, strongly coriaceous, ± striate; petals 3, distinct, imbricate, thinly coriaceous, with very brief valvate tips; staminodes connate in a brief irregularly toothed ring; gynoecium trilocular, triovulate, obpyriform, stigmas 3, tightly appressed in bud, ovule form unknown. Fruit relatively large, 1-seeded, ± ovoid with a short triangular beak, the perianth segments persisting as a cupule; epicarp smooth, mesocarp rather dry with abundant longitudinal fibres, the outer fine, the inner broad and flattened, easily separated from endocarp, endocarp woody, relatively thick, marked with 3 indistinct pores, 1 opposite the embryo. Seed broadly ovoid, attached near the base with a broad hilum, with numerous anastomosing raphe branches, endosperm deeply ruminate; embryo lateral below the equator. Germination adjacent-ligular; eophyll entire, lanceolate. Cytology: 2n = 36.