Ricinus L.

Scientific Description

Family Euphorbiaceae.

Habit and leaf form. Shrubs, or herbs; laticiferous, or non-laticiferous and without coloured juice, or with coloured juice. Plants succulent, or non-succulent. Herbs annual. Mesophytic, or xerophytic. Leaves very large; alternate; spiral; ‘herbaceous’, or leathery, or fleshy; petiolate (petiole very long, glandular); non-sheathing; gland-dotted, or not gland-dotted; simple. Leaf blades dissected (deeply palmately lobed); pinnately veined, or palmately veined. Leaves with stipules, or without stipules. Stipules when present, connate into a sheath; 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. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes, or in panicles. Inflorescences terminal, or axillary; loose, on thick peduncles, the male flowers below the females. Flowers shortly pedicellate; bracteate; small; regular. Free hypanthium absent. Hypogynous disk present, or absent. Perianth sepaline; 5; 1 -whorled. Calyx 5; 1 -whorled; gamosepalous (connate basally); regular; persistent, or not persistent. Fertile stamens present, or absent (female flowers). Androecium 20–1000 (i.e. ‘numerous’). Androecial members branched (filaments repeatedly branched); free of the perianth; free of one another, or coherent. Androecium exclusively of fertile stamens. Stamens 20–1000; polystemonous; erect in bud, or inflexed in bud. Anthers dehiscing via longitudinal slits (cells globular); 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; superior. Ovary plurilocular; 3 locular. Styles 3; free, or partially joined; simple, or forked; apical. Stigmas 3, or 6 (red, fringed with tubercular projections); dry type; papillate, or non-papillate; Group II type. Placentation axile, or apical. Ovules 1 per locule; pendulous; epitropous; with ventral raphe, or with dorsal raphe; arillate; orthotropous, or anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy (woody); dehiscent; a capsule (trigonous, with long spine-tipped projections). Seeds endospermic. Endosperm oily. Seeds arillate. Cotyledons 2 (usually wider than the radicle). Embryo straight, or curved. Testa smooth. Seedling. Germination phanerocotylar, or cryptocotylar.

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

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