Dwarf or creeping to large, solitary or clustered, armed, pleonanthic, dioecious palms. Stem, when developed, often clothed with spirally arranged leaf bases. Leaves induplicate, pinnate, usually marcescent; sheath forming a fibrous network; petiole very short to well developed, adaxially channelled to flattened or ridged, abaxially rounded; rachis elongate, tapering, adaxially rounded or flat to angled, abaxially rounded to flat, usually terminating in a leaflet; leaflets single-fold, acute, regularly arranged or variously grouped, the proximal few modified as spines (acanthophylls), parallel-veined, midrib usually evident abaxially, often bearing scales, emergent leaves frequently with brown floccose indumentum and/or wax, transverse veinlets obscure. Inflorescences interfoliar, branching to 1 order, the staminate and pistillate superficially similar; peduncle flattened, short to elongate, in the pistillate frequently elongating after fertilization, bearing an often caducous, sometimes bivalved, 2-keeled, glabrous or floccose-hairy prophyll; other bracts inconspicuous; rachis flattened, usually shorter than the peduncle; rachillae unbranched, numerous, often in groups in a spiral along the rachis, somewhat adnate above small triangular bracts, the rachillae bearing spirally arranged, low triangular bracts, each subtending a solitary flower. Staminate flowers with 3 sepals connate in a low cupule; petals 3, ± valvate, acute or rounded, much exceeding the calyx; stamens usually 6 (rarely 3 or 9), filaments short, erect, the anthers linear, latrorse; pistillode absent, or of 3 abortive carpels, or a minute trifid vestige. Pollen ellipsoidal, bi-symmetric or very slightly asymmetric; aperture a distal sulcus; ectexine tectate, coarsely perforate, finely reticulate, foveolate, or perforate-rugulate; aperture margin slightly finer, psilate or scabrate; infratectum columellate; longest axis 17–30 µm [11/13]. Pistillate flowers globose; sepals connate in a 3-lobed cupule; petals imbricate, strongly-nerved, about twice as long as the calyx or more; staminodes usually 6, scale-like or connate in a low cupule; carpels 3, distinct, follicular, ± ovoid, narrowed into a short, recurved, exserted stigma, ovule attached adaxially at the base, anatropous. Fruit usually developing from 1 carpel, ovoid to oblong with apical stigmatic remains; epicarp smooth, mesocarp fleshy, endocarp membranous. Seed elongate, terete or plano-convex, and deeply grooved with intruded seed coat below the elongate raphe, hilum basal, rounded, endosperm homogeneous or rarely ruminate (Phoenix anadamanensis); embryo lateral or subbasal. Germination remote-tubular; eophyll undivided, narrowly lanceolate. Cytology: 2n = 32, 36.
The Date Palms. Solitary or clustering dioecious pinnate-leaved palms of the Old World, usually in arid or semi-arid areas, sometimes in mangrove or monsoon forest, instantly recognisable by the induplicate leaflets with spine-like tips, and the acanthophylls at the leaf base; inflorescence with a single large bract.
Most species are plants of semi-arid regions but grow near water courses, oases, or underground water sources; a few species are found in tropical monsoonal areas. Phoenix paludosa occurs in the Asian perhumid regions, where it is confined to the landward fringe of mangrove forest. Phoenix roebelenii grows as a rheophyte on the banks of the Mekong and some of its tributaries.
14 species ranging from the Atlantic islands through Africa, Crete, the Middle East and India to Hong Kong, Taiwan, Philippines, Sumatra and Malaya. Widely cultivated as ornamentals, one species, Phoenix dactylifera, the date palm, is a major economic plant, now widespread in semi-arid areas as a fruit tree.
The genus is immensely important from an economic point of view. It includes not only the date palm, the major crop of several Middle Eastern countries and of lesser importance elsewhere, but also other species that are widely used as sources of fibre for weaving, starch, sugar, and a multiplicity of purposes such as thatch and fuel. Many species are widely grown as ornamentals. Phoenix roebelenii is commercially important as a pot plant. Species are known to hybridise freely. For references on uses, see Johnson (1983a, 1984). For a summary of uses, see Johnson (1985).