Wilsonia R.Br.

Scientific Description

Family Convolvulaceae.

Habit and leaf form. Herbs, or shrubs; laticiferous, or non-laticiferous and without coloured juice. Plants succulent; autotrophic. Herbs perennial; plants with neither basal nor terminal concentrations of leaves. Trailing or self supporting. Helophytic, mesophytic, and xerophytic. Leaves alternate; spiral; fleshy; imbricate, or not imbricate; petiolate to sessile; non-sheathing; simple. Leaf blades entire; pinnately veined, or palmately veined; cross-venulate; cordate, or hastate, or sagittate. Leaves without stipules; without a persistent basal meristem. Leaf anatomy. Hairs present (hairs bifid), or absent. Stem anatomy. Nodes unilacunar. Secondary thickening anomalous, or developing from a conventional cambial ring; via concentric cambia, or from a single cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence and flower features. Flowers solitary; axillary; subsessile to sessile; ebracteate; small to medium-sized; regular; 5(–6) merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present; annular. Perianth with distinct calyx and corolla; 10(–12); 2 -whorled; isomerous. Calyx 5(–6); 1 -whorled; gamosepalous. Calyx lobes markedly shorter than the tube. Calyx hairy; imbricate; tubular to campanulate; persistent; with the median member posterior. Corolla 5(–6); 1 -whorled; gamopetalous; imbricate (with induplicate margins); campanulate (with a slender tube, or salver-shaped); regular; glabrous abaxially; glabrous adaxially; white, or yellow. Androecium 5. Androecial members adnate (to the corolla); all equal, or markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion in the throat of the corolla tube. Stamens becoming exserted; oppositisepalous. Filaments glabrous. Anthers basifixed; twisted spirally after dehiscence; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled, or 1 celled (when ovary only partially divided). Gynoecium syncarpous; synstylovarious; superior. Ovary unilocular, or plurilocular; 1 locular, or 2 locular. Gynoecium median. Styles 1; forked (branches filiform); apical; becoming exserted. Stigmas 2; 1 - lobed; capitate; dry type; papillate; Group II type. Placentation basal. Ovules 1 per locule, or 2 per locule; ascending; apotropous; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy; not hairy; indehiscent; capsular-indehiscent; 1 seeded, or 2 seeded. Seeds endospermic. Endosperm oily. Seeds conspicuously hairy, or not conspicuously hairy. Cotyledons 2. Embryo chlorophyllous; straight, or curved. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia, South Australia, New South Wales, Victoria, Australian Capital Territory, and Tasmania. South-West Botanical Province.

Additional characters Stigmas the stigmatic area globose. Corolla lobes spreading.