Antidesma L.

Scientific Description

Family Euphorbiaceae.

Habit and leaf form. Trees, or shrubs; non-laticiferous and without coloured juice. Plants succulent, or non-succulent. Mesophytic, or xerophytic. Leaves small to medium-sized; alternate; spiral, or distichous; ‘herbaceous’, or leathery, or fleshy; shortly petiolate; non-sheathing; gland-dotted, or not gland-dotted; simple. Leaf blades entire; pinnately veined. Leaves without stipules; without a persistent basal meristem. Leaf anatomy. Urticating hairs present, or absent. Stem anatomy. Nodes tri-lacunar, or unilacunar. Secondary thickening developing from a conventional cambial ring, or anomalous; from a single cambial ring.

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Unisexual flowers present. Plants dioecious. Male flowers with pistillodes (the rudimentary ovary lobed). Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes (the flowers in the axils of bracts). Inflorescences simple, or compound; axillary. Flowers bracteate; small; regular. Free hypanthium absent. Hypogynous disk present; annular. Perianth sepaline; 3–5; 1 -whorled. Calyx 3–5; 1 -whorled; gamosepalous; shallowly or deeply lobed; regular. Fertile stamens present, or absent (female flowers). Androecium 2–5(–10) (arising from the disc or alternating with disc glands). Androecial members free of the perianth; free of one another (? or nearly so). Androecium exclusively of fertile stamens. Stamens 2–5(–10); reduced in number relative to the adjacent perianth, or isomerous with the perianth, or diplostemonous; erect in bud, or inflexed in bud. Anthers dehiscing via longitudinal slits; extrorse, or introrse; bisporangiate, or tetrasporangiate; the connective thickened and more or less 2-lobed. Fertile gynoecium present, or absent (male flowers). Gynoecium 2 carpelled. The pistil 1 celled, or 2 celled. Gynoecium syncarpous; synovarious, or synstylovarious; superior. Ovary unilocular, or plurilocular; 1 locular, or 2 locular. Styles 3; free, or partially joined; forked; apical. Stigmas 6; dry type; papillate, or non-papillate; Group II type. Placentation axile, or apical. Ovules 2 per locule; pendulous; epitropous; with ventral raphe, or with dorsal raphe; collateral; non-arillate; anatropous.

Fruit and seed features. Fruit fleshy; indehiscent; a drupe (small, more or less oblique); 1 seeded. Seeds endospermic. Endosperm oily. Seeds non-arillate. Cotyledons 2 (wider but scarcely exceeding the radicle). Embryo straight, or curved. Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Mustard-oils present, or absent.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province.