Spartothamnella Briq.

Scientific Description

Family Lamiaceae.

Sometimes included in Chloanthaceae, Verbenaceae.

Habit and leaf form. Shrubs (undershrubs); evergreen; resinous (glutinous secretions), or not resinous. ‘Normal’ plants to switch-plants (somewhat switch-plant-like, owing to sparse leaves and broom-like habit). Leaves well developed, or much reduced. Plants unarmed. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves. Young stems tetragonal. To 0.5–2(–3) m high. Leptocaul. Leaves small; not fasciculate; opposite; decussate; not decurrent on the stems; leathery, or membranous; not imbricate; subsessile to sessile; aromatic, or without marked odour; simple. Leaf blades entire; flat; linear, or lanceolate, or oblong, or ovate; elliptic, or oblong, or ovate (often narrowly); pinnately veined; cross-venulate. Mature leaf blades adaxially glabrous, or pubescent; abaxially pubescent. Leaves without stipules; without a persistent basal meristem. Leaf anatomy. Hairs present, or absent; glandular hairs absent, or present (when present, sparsely on young leaves); complex hairs present, or absent. Complex hairs stellate. Stem anatomy. Secondary thickening anomalous; via concentric cambia. Roots. Aerial roots absent.

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

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; axillary. Inflorescence few-flowered. Flowers in cymes (up to 3-flowered). Inflorescences axillary; flowers 1–3 in a short axillary cymes. Flowers pedicellate to subsessile; bracteate; bracteolate (2-lateral ones); small (very); very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk absent. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5 (deeply lobed); 1 -whorled; gamosepalous; blunt-lobed, or toothed; exceeded by the corolla to exceeding the corolla; cyathiform; regular; persistent; non-accrescent. Calyx lobes ovate, or triangular. Corolla present; 5 (2-lipped or unequally 5-lobed in the upper half, lobes spreading, the anterior (i.e. the middle lower) lobe larger than the others); 1 -whorled; gamopetalous; blunt-lobed; imbricate; unequal but not bilabiate to bilabiate; hairy abaxially; hairy adaxially (villous in the throat); white (sometimes greenish or creamy white); deciduous. Corolla members entire. 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. Staminal insertion near the base of the corolla tube, or midway down the corolla tube. Stamens becoming exserted (sometimes markedly exserted); didynamous; all more or less similar in shape; isomerous with the perianth; fertile stamens representing the posterior-lateral pair and the anterior-lateral pair; oppositisepalous. Filaments hairy (towards base), or glabrous (in upper half); filiform. Anthers dorsifixed (more or less reniform, cells divergent); dehiscing via longitudinal slits (the slits joining). Gynoecium 2 carpelled. The pistil 4 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious (styles free in upper part); superior. Ovary plurilocular; 2 locular (morphologically), or 4 locular (ostensibly, via false septa). Locules secondarily divided by ‘false septa’. Gynoecium median. Ovary summit hairy, the hairs not confined to radiating bands. Gynoecium stylate. Styles 1; forked; from a depression at the top of the ovary; apical; much longer than the ovary at anthesis; becoming exserted; deciduous; hairless (glabrous). Stigmas 2. Placentation axile. Ovules 2 per locule (per carpel), or 1 per locule (ostensibly, i.e. per locellus); pendulous; non-arillate; hemianatropous.

Fruit and seed features. Fruit fleshy; indehiscent; a drupe. The drupes with separable pyrenes (the hard, sculptured endocarp separating into 4 one-seeded fruitlets). Fruit 4 celled; 4 locular. Dispersal unit the fruit. Dispersal possibly avian: fruits fleshy, red. Fruit 1–4 seeded. Seeds non-endospermic; minute to small. Cotyledons 2. Embryo straight (with thick cotyledons and an inferior radicle).

Special features. Calyx limb 5 lobed. Corolla tube exceeding the calyx.

Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia, South Australia, Northern Territory, Queensland, and New South Wales. A genus of 3 species; 1 species in Western Australia; 0 endemic to Western Australia.

Etymology. From genus Spartothamnus and the diminutive suffix -ell-.