Common name. Teatrees. Family Myrtaceae.
Habit and leaf form. Shrubs; evergreen; bearing essential oils. Plants with neither basal nor terminal concentrations of leaves. Young stems with stem flanges. To 1 m high. Leptocaul. Helophytic, or mesophytic. Leaves minute to medium-sized; alternate; leathery; petiolate to subsessile; gland-dotted; aromatic; edgewise to the stem, or with ‘normal’ orientation; simple; epulvinate. Leaf blades dorsiventral, or isobilateral, or centric; entire; flat, or folded (apparently); linear, or lanceolate, or oblong, or ovate; linear, or ovate, or oblong; pinnately veined, or parallel-veined, or one-veined; cross-venulate, or without cross-venules. Mature leaf blades adaxially glabrous; abaxially glabrous. Leaves without stipules; without a persistent basal meristem. Leaf anatomy. 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. Pollination mechanism unspecialized.
Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’. The terminal inflorescence unit cymose. Inflorescences of 1-few flowers at the end of a modified stem which is frondobracteose and usually with the terminal bud aborted. Flowers bracteate (the bracts intergrading with the leaves); bracteolate, or ebracteolate; small to medium-sized; regular, or somewhat irregular. The floral asymmetry (when noticeable) involving the androecium. Flowers 5 merous; cyclic. Free hypanthium present (petals ‘inserted on the calyx’); campanulate. Hypogynous disk present. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; imbricate, or valvate; exceeded by the corolla; regular; persistent. Calyx lobes triangular. Corolla present; 5; 1 -whorled; polypetalous; imbricate; regular; hairy abaxially (usually); glabrous adaxially; plain, or with contrasting markings; white, or pink, or pink and red. Petals obovate. Androecial members indefinite in number. Androecium 17–24. Androecial members branched. Androecial sequence determinable, or not determinable. Androecial members if ‘many’, maturing centripetally; free of the perianth; all equal, or markedly unequal; free of one another. Stamens 17–24 (1 opposite each petal and 2–4 opposite each sepal); shorter than the petals; polystemonous; alternisepalous and oppositisepalous; both opposite and alternating with the corolla members; erect in bud, or inflexed in bud. Filaments not geniculate; filiform. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate; appendaged, or unappendaged. Gynoecium 3 carpelled. The pistil 3 celled. Gynoecium syncarpous; eu-syncarpous; inferior, or partly inferior. Ovary plurilocular; 3 locular. Epigynous disk present, or absent. Gynoecium stylate. Styles 1; simple; from a depression at the top of the ovary; apical. Stigmas 1; peltate. Placentation axile. Ovules several per locule, only the lowest one maturing; pendulous to horizontal; non-arillate; hemianatropous (and peltate).
Fruit and seed features. Fruit non-fleshy (woody); dehiscent; a capsule (3-valved). Capsules septicidal, or loculicidal, or denticidal, or circumscissile. Fruit 3 seeded. Seeds 1 per locule. Seeds non-endospermic. Cotyledons 2. Testa with a close pattern of minute protuberances.
Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia. South-West Botanical Province.