Drypetes Vahl

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 very large; alternate; spiral, or distichous; leathery; petiolate; non-sheathing; gland-dotted, or not gland-dotted; simple. Leaf blades entire; pinnately veined. Leaves with stipules. Stipules scaly, or leafy, or spiny, or represented by glands; caducous (usually), or persistent. 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, or hermaphrodite. Unisexual flowers present, or absent. Plants dioecious, or hermaphrodite. Male flowers without pistillodes. Entomophilous.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, axillary; when aggregated, in clusters, sometimes the male flowers in short racemes. Inflorescences axillary, or cauliflorous. Flowers bracteate, or ebracteate; minute to small; regular. Floral receptacle developing an androphore, or with neither androphore nor gynophore. Free hypanthium absent. Hypogynous disk present; annular. Perianth sepaline; 4, or 5; 1 -whorled. Calyx 4, or 5; 1 -whorled; polysepalous, or gamosepalous; imbricate; regular; not persistent. Fertile stamens present, or absent (female flowers). Androecial members indefinite in number. Androecium 3–50. Androecial members free of the perianth; free of one another. Androecium exclusively of fertile stamens. Stamens 3–50; reduced in number relative to the adjacent perianth to polystemonous; erect in bud, or inflexed in bud. Anthers dehiscing via longitudinal slits; extrorse, or introrse; bilocular to four locular; bisporangiate, or tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 2 carpelled, or 3 carpelled. The pistil 1–3 celled. Gynoecium syncarpous; synovarious, or synstylovarious; superior. Ovary unilocular, or plurilocular; 1–3 locular. Styles 1–3; free, or partially joined; simple, or forked (? sometimes 2-lobed); apical. Stigmas 1–6; 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 (globular or ellipsoid, exocarp coriaceous or crustaceous). The drupes with one stone. Seeds oblong in outline and grooved down one side; endospermic. Endosperm oily. Seeds non-arillate. Cotyledons 2 (usually wider than the radicle). Embryo straight, or curved. Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Mustard-oils present.

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