Habit and leaf form. Shrubs, or herbs. Perennial. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves. Mesophytic. Leaves small to large; opposite, or alternate and opposite, or whorled (in lower leaves); when alternate, spiral; decussate; petiolate, or sessile; non-sheathing; simple. Leaf blades entire; conspicuously asymmetric, or not conspicuously asymmetric; flat; elliptic to ovate; pinnately veined, or palmately veined; cross-venulate; cuneate at the base to rounded at the base. Leaves with stipules. Stipules interpetiolar, or intrapetiolar; free of one another; caducous, or persistent. Leaf blade margins entire, or serrate to dentate; flat. Leaves without a persistent basal meristem. Leaf anatomy. Urticating hairs absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.
Reproductive type, pollination. Fertile flowers functionally male and functionally female (usually), or functionally male, or functionally female. Unisexual flowers present. Plants monoecious, or dioecious (rarely). Female flowers without staminodes. Male flowers with pistillodes. Anemophilous.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescence many-flowered. Flowers in cymes (sessile cymules), or in spikes (or sometimes spike-like when leaves not developed), or in fascicles (or small clusters). Inflorescences simple. The terminal inflorescence unit cymose. Inflorescences axillary; without involucral bracts. Flowers pedicellate, or sessile to subsessile; bracteate; minute; regular; 3–5 merous. Hypogynous disk absent. Perianth sepaline, or vestigial to absent (sometimes, in female flowers); 3–5; 1 -whorled. Calyx present; (the perianth being thus interpreted) 3–5; 1 -whorled; gamosepalous (male flowers scarcely so); in female flowers entire (or very shortly lobed), or lobed (in male flowers). Calyx lobes markedly shorter than the tube (in female flowers, if present), or markedly longer than the tube (in male flowers). Calyx hairy; imbricate, or valvate; of female flowers, tubular; regular; persistent; accrescent, or non-accrescent. Corolla absent. Androecium present, or absent (in female flowers). Fertile stamens present, or absent (female flowers). Androecial members definite in number. Androecium 3–5. Androecial members free of the perianth; all equal; free of one another; 1 -whorled. Stamens 3–5; all more or less similar in shape; isomerous with the perianth; oppositisepalous; inflexed in bud (uncoiling elastically); filantherous. Anthers dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium ostensibly 1 carpelled (i.e. with no obvious evidence of more than one carpel). The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium monomerous (ostensibly), or syncarpous (theoretically); of one carpel (at least, usually with no evidence of syncarpy), or synstylovarious to eu-syncarpous (theoretically); superior. Carpel (if treated as monomeric) shortly stylate; apically stigmatic; (ifthe gynoecium is considered monomerous) 1 ovuled. Placentation basal. Ovary unilocular; (if the gynoecium is considered as pseudomonomerous) 1 locular. Gynoecium stylate (the style single). Styles becoming exserted; deciduous. Placentation if recognised as syncarpous, basal. Ovules in the single cavity 1; funicled, or sessile; ascending; non-arillate; orthotropous to hemianatropous.
Fruit and seed features. Fruit non-fleshy. The fruiting carpel indehiscent; (if the gynoecium is considered monomerous) an achene. Fruit indehiscent; (if the gynoecium is considered syncarpous) achene-like, or a samara (when fruit winged). Dispersal unit the fruit. Fruit 1 seeded. Seeds scantily endospermic, or non-endospermic. Endosperm oily, or not oily. Cotyledons 2. Embryo straight.
Geography, cytology, number of species. World distribution: widespread in the tropics of America, Africa and Asia, with 2 species in Australia. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province. A genus of 70 species; 1 species in Western Australia; 0 endemic to Western Australia.
Etymology. After Pierre Charles Marie de Pouzolz (1785–1858), French botanist.