Claoxylon A.Juss.

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 medium-sized to large; 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. Stipules small; caducous, 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. Unisexual flowers present. Plants dioecious. Male flowers without pistillodes. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes (male flowers in clusters at each bract along the raceme, female flowers usually solitary at each bract). Inflorescences solitary or paired; axillary. 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; 2- or 3-lobed. Perianth sepaline; 2–4; 1 -whorled. Calyx 2–4 (in male flowers), or 3 (in female flowers, usually); 1 -whorled; gamosepalous (in female flowers); regular. Fertile stamens present, or absent (female flowers). Androecium 10–200. Androecial members free of the perianth; free of one another (filaments inserted on a receptacle or disc along with erect glands), or coherent (? then almost free). Androecium exclusively of fertile stamens. Stamens 10–200; polystemonous; erect in bud, or inflexed in bud. Anthers linear; basifixed; dehiscing via longitudinal slits; extrorse, or introrse; bisporangiate, or tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 3 carpelled. The pistil 3 celled. Gynoecium syncarpous; synovarious, or synstylovarious (depending on interpretation of partially connate styles); superior. Ovary plurilocular; 3 locular. Styles 3; free, or partially joined (connate towards the base); simple; apical. Stigmas 3; dry type; papillate; Group II type. Placentation axile, or apical. Ovules 1 per locule; pendulous; epitropous; with ventral raphe, or with dorsal raphe; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy; a schizocarp. Mericarps 3. Fruit elastically dehiscent (schizocarpic capsules often splitting elastically), or passively dehiscent. Seeds 1 per mericarp. Seeds globular; 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, 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.