Small unarmed trees, with stems covered with pale gray rind. Leaves orbicular, or truncate at the base, thick and firm, usually silvery white on the lower surface, divided to below the middle into narrow acuminate parted segments with thickened margins and midribs; rachis a narrow border, with thin usually undulate margins; ligule thick, concave, pointed, lined while young with hoary tomentum; petioles compressed, rounded above and below, thin and smooth on the margins, with large clasping bright mahogany-red sheaths of slender matted fibres covered with thick hoary tomentum. Spadix interfoliar, stalked, its primary branches short, alternate, flattened, incurved, with numerous slender rounded flower-bearing branchlets; spathes numerous, tubular, coriaceous, cleft and more or less tomentose at the apex. Flowers opening in May and June, and occasionally irregularly in the autumn, solitary, perfect; perianth 6-lobed; stamens inserted on the base of the perianth, with subulate filaments thickened and only slightly united at the base, or nearly triangular and united into a cup adnate to the perianth, and oblong anthers; ovary 1-celled, gradually narrowed into a stout columnar style crowned by a large funnel-formed flat or oblique stigma; ovule basilar, erect. Fruit a globose drupe with juicy bitter ivory-white flesh easily separable from the thin-shelled tawny brown nut. Seed free, erect, slightly flattened at the ends, with an oblong pale conspicuous subbasilar hilum, a short-branched raphe, a thin coat, and uniform albumen more or less deeply penetrated by a broad basal cavity; embryo lateral. Thrinax is confined to the tropics of the New World and is distributed from southern Florida through the West Indies to the shores of Central America. Seven or eight species are now generally recognized. The wood of the Florida species is light and soft, with numerous small fibro-vascular bundles, the exterior of the stem being much harder than the spongy interior. The stems are used for the piles of small wharves and turtle-crawls, and the leaves for thatch, and in making hats, baskets, and small ropes. _Thrinax_, from θρῖναξ, is in allusion to the shape of the leaves. CONSPECTUS OF THE NORTH AMERICAN SPECIES.