Leonotis (Pers.) R.Br.

Scientific Description

Family Lamiaceae.

Habit and leaf form. Shrubs, or herbs; evergreen; bearing essential oils. Plants unarmed. Perennial. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves. Young stems usually tetragonal. To 0.6–2 m high. Leaves small to medium-sized; not fasciculate; opposite; ‘herbaceous’; not imbricate; petiolate; aromatic; simple; epulvinate. Leaf blades dissected; flat; broadly ovate, or elliptic (narrow); pinnately veined; cross-venulate; cordate to cuneate at the base, or rounded at the base. Mature leaf blades adaxially pilose (sparsely hairy); abaxially pilose (sparsely hairy). Leaves without stipules. Leaf blade margins crenate, or serrate; flat. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present; glandular hairs present. Urticating hairs absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous, or ornithophilous; usually via hymenoptera, or via lepidoptera, or via diptera.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescence many-flowered. Flowers in verticils. The terminal inflorescence unit cymose. Inflorescences axillary; an interrupted spike of globular, many flowered verticillasters. Flowers pedicellate; medium-sized; very irregular; zygomorphic; cyclic; tetracyclic. Floral receptacle developing a gynophore, or with neither androphore nor gynophore. Free hypanthium absent. Perianth with distinct calyx and corolla; 4–10; 2 -whorled; isomerous, or anisomerous. Calyx present; disguisedly 5; 1 -whorled; gamosepalous; entire, or lobed; usually blunt-lobed, or toothed; imbricate, or open in bud; exceeded by the corolla; funnel-shaped, or tubular; regular to unequal but not bilabiate; non-fleshy; persistent; with the median member posterior. Calyx lobes triangular. Corolla present; disguisedly 5; 1 -whorled; gamopetalous; blunt-lobed; imbricate; tubular; bilabiate (the upper lip erect, elongated, the lower one short and 3-lobed); densely orange hairy abaxially; glabrous adaxially (except the lobes which are densely white-hairy); plain; bright orange. Corolla members entire. Androecium present. Fertile stamens present. Androecial members definite in number. Androecium 4. Androecial members adnate; markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4; becoming exserted; didynamous (lower pair longer); all more or less similar in shape; reduced in number relative to the adjacent perianth; fertile stamens representing the posterior-lateral pair and the anterior-lateral pair; oppositisepalous; all alternating with the corolla members. Filaments hairy; filiform (dilated). Anthers connivent, or separate from one another; dorsifixed; versatile, or non-versatile; dehiscing via longitudinal slits; introrse; bilocular (anther cells divaricate); tetrasporangiate; unappendaged. Pollen shed as single grains. Fertile gynoecium present. Gynoecium 2 carpelled (the carpels deeply lobed to mimic G4). The pistil 4 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 2 locular (originally), or 4 locular (by intrusions of the ovary wall constituting ‘ false septa’). Locules secondarily divided by ‘false septa’. Gynoecium median; stylate. Styles 1; simple; from a depression at the top of the ovary; ‘gynobasic’; becoming exserted. Stigmas 1 (reduced to a tiny tooth); 2 - lobed. Placentation basal. Ovules 2 per locule, or 1 per locule (two per original loculus, but one per locellus); ascending; apotropous; non-arillate; anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; a schizocarp. Mericarps (2–)4; comprising nutlets. Seeds endospermic to non-endospermic. Embryo well differentiated. Cotyledons 2. Embryo straight.

Special features. The flowering nodes separated by extended internodes. 8–15 flowers subtended by each floral leaf. Calyx limb when present, 8–10 lobed. Corolla tube much exceeding the calyx; curved. The upper lip of the corolla incorporating 2 members, the lower 3; (posterior, adaxial) lip of the corolla entire; upper (adaxial) lip of the corolla markedly concave. Lower (abaxial) lip of the corolla 3 lobed. Stamens ascending. The anterior pair of stamens exceeding the posterior pair.

Geography, cytology, number of species. Adventive. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, Queensland, and New South Wales. A genus of ca 15 species; 1 species in Western Australia; 0 endemic to Western Australia.

Etymology. From the Greek for "lion" and "ear"; the upper lip of the corolla is erect, concave and bearded.