Bridelia Willd.

Scientific Description

Family Euphorbiaceae.

Habit and leaf form. Trees, or shrubs; non-laticiferous and without coloured juice. Plants succulent, or non-succulent. Self supporting, or climbing; scrambling. Mesophytic, or xerophytic. Leaves small to medium-sized; alternate; spiral, or distichous; ‘herbaceous’, or leathery, or fleshy; petiolate; non-sheathing; gland-dotted, or not gland-dotted; simple. Leaf blades entire; pinnately veined. Leaves with stipules, or without stipules. Stipules small; caducous. Leaves 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 monoecious (usually). The unisexual flowers in the same or in separate clusters. Male flowers with pistillodes (rudimentary ovary small), or without pistillodes. Entomophilous.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’ (then clustered); in glomerules, or in spikes. Inflorescences axillary. Flowers pedicellate to sessile; bracteate, or ebracteate; minute to small; regular. Floral receptacle developing an androphore. Free hypanthium absent. Hypogynous disk present; broad, with an entire or slightly lobed margin in male flowers, or a cup-shaped margin surrounding the ovary in female flowers. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx 5; gamosepalous (towards the base). Calyx lobes markedly longer than the tube. Calyx spreading; valvate; regular; fleshy (and thick); persistent, or not persistent. Corolla present (spathulate or clawed), or vestigial (then minute, scale-like); 5. Fertile stamens present, or absent (female flowers). Androecium 5. Androecial members free of the perianth; free of one another (if filaments interpreted as arising from an androphore), or coherent (connate towards the base in a central column). Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; erect in bud, or inflexed in bud. Anthers ovoid to ellipsoid; dorsifixed, or basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 2(–3) carpelled. The pistil (1–)2(–3) celled. Gynoecium syncarpous; synovarious, or synstylovarious (depending on interpretation of partially connate styles); superior. Ovary unilocular, or plurilocular; (1–)2(–3) locular. Styles usually 2; free, or partially joined (connate towards the base); often forked (2-lobed); apical. Stigmas 4; 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; arillate, or non-arillate; anatropous.

Fruit and seed features. Fruit fleshy (with fleshy mesocarp and hard endocarp which sometimes splits); indehiscent, or a schizocarp. Mericarps 2. Fruit when indehiscent, a berry, or a drupe (small); 1–2(–3) locular; elastically dehiscent (schizocarpic capsules often splitting elastically), or passively dehiscent; 1–3 seeded. Seeds 1 per locule; 1 per mericarp. Seeds with a longitudinal groove on one face; endospermic. Endosperm fleshy or membranaceous. Cotyledons 2 (usually wider than the radicle). Embryo straight, or curved (slightly). Testa smooth. 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.