Phoenix L.

Scientific Description

Family Arecaceae.

Habit and leaf form. Dwarf or creeping to large ‘arborescent’ (palms, trunk usually unbranched, covered with persistent petiole stubs); evergreen. Plants spiny. Pachycaul. Mesophytic, or xerophytic. Leaves small to very large; alternate; spiral; leathery; petiolate; sheathing. Leaf sheaths tubular (sheath forming a fibrous network); with joined margins. Leaves compound; epulvinate; pinnate (leaflets single-fold, regularly arranged or variously grouped, with acute apices, the proximal few modified as spines); imparipinnate. Leaf blades without cross-venules. Leaves ligulate, or eligulate; without a persistent basal meristem (presumably). Vernation conduplicate. Leaves becoming compound by ontogenetically predetermined splitting. Vegetative anatomy. Plants with silica bodies (spheroidal). Leaf anatomy. Leaf blade epidermis without differentiation into ‘long’ and ‘short’ cells. Stem anatomy. Secondary thickening absent.

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Unisexual flowers present. Plants dioecious. Female flowers with staminodes (usually 6, scale-like or connate in a low cupule). Male flowers without pistillodes, or with pistillodes (then comprised of 3 abortive carpels, or a minute trifid vestige). Floral nectaries present, or absent. Anemophilous, or entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in panicles. The terminal inflorescence unit cymose. Inflorescences axillary; flowers spirally arranged on unbranched rachillae; spatheate (initially enclosing the inflorescence). Flowers sessile; small; more or less regular; 3 merous; cyclic. Perigone tube absent. Perianth with distinct calyx and corolla, or of ‘tepals’; 6; 2 -whorled (3+3); isomerous; sepaloid and petaloid; different in the two whorls; white, or cream. Calyx if outer whorl so interpreted, 3; gamosepalous. Corolla if inner whorl so interpreted, 3 (exceeding the calyx); polypetalous; valvate (male flowers), or imbricate (female flowers). Fertile stamens present, or absent (female flowers). Androecium 6, or 3 (rarely), or 9 (rarely). Androecial members adnate (to the perianth); free of one another. Androecium exclusively of fertile stamens. Stamens 3, or 6, or 9; diplostemonous (usually), or isomerous with the perianth, or triplostemonous. Anthers linear; dehiscing via longitudinal slits; latrorse; tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 3 carpelled (usually only one carpel developing). Carpels isomerous with the perianth. Gynoecium apocarpous; eu-apocarpous. Carpel apically stigmatic. Placentation basal. Stigmas dry type; papillate; Group II type. Ovules non-arillate; anatropous.

Fruit and seed features. Fruit fleshy; not an aggregate (usually), or an aggregate (when more than one carpel develops). The fruiting carpel indehiscent; a berry, a berry-like drupe or follicular, with apical stigmatic remains. Fruit 1 seeded. Seeds endospermic. Endosperm ruminate, or not ruminate; oily, or not oily. Seeds without starch. Cotyledons 1. Embryo achlorophyllous. Seedling. Germination consistently cryptocotylar (regardless of cotyledon form). Hypocotyl internode absent. Seedling collar not conspicuous. Cotyledon hyperphyll elongated, or compact; non-assimilatory. Coleoptile present, or absent. Seedling cataphylls absent. First leaf dorsiventral. Primary root persistent, or ephemeral.

Physiology, biochemistry. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Adventive. Australian states and territories: Western Australia and Victoria. N = 18.

Additional characters Pollen grains sulcate. Perianth of male flowers with distinct calyx and corolla, or of ‘tepals’; 6. Perianth of female flowers with distinct calyx and corolla, or of ‘tepals’; 6.