Habit and leaf form. Trees, or shrubs. Young stems cylindrical, or tetragonal. Helophytic to xerophytic. Leaves usually opposite; petiolate, or subsessile; gland-dotted, or not gland-dotted; simple. Leaf blades entire; elliptic, or ovate; pinnately veined; cross-venulate. Leaves with stipules. Stipules caducous (minute). Leaf blade margins entire. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present, or absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants homostylous, or heterostylous. Entomophilous.
Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; paniculate in cymes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal and axillary. Flowers two bracteolate; minute to medium-sized; regular; 6 merous; partially acyclic. The androecium acyclic. Floral receptacle developing an androphore, or with neither androphore nor gynophore. Free hypanthium present; campanulate, or obconic (infundibular); ridged, angular or subulate; sinus appendages prominent or obscure. Hypogynous disk present, or absent. Perianth with distinct calyx and corolla; (3–)8–16(–32); 2 -whorled; isomerous. Calyx present, or absent; 6; 1 -whorled; gamosepalous; blunt-lobed; lobes valvate; tubular, or campanulate, or urceolate; unequal but not bilabiate, or regular; persistent. Epicalyx present, or absent. Corolla present; 6; 1 -whorled; polypetalous; plicate; unequal but not bilabiate, or regular; pink to purple. Petals oblong; clawed. Androecial members indefinite in number. Androecium 100 (‘many’). Androecial sequence determinable. Androecial members maturing centripetally; adnate (to the hypanthium, low down); all equal, or markedly unequal; free of one another; 1–3 -whorled (or several). Androecium exclusively of fertile stamens. Stamens 50–100 (many); attached inside the hypanthium; reduced in number relative to the adjacent perianth to isomerous with the perianth to polystemonous; alternisepalous, or oppositisepalous; inflexed in bud, or erect in bud. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 3–6 carpelled. The pistil 3–6 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 3–6 locular; sessile. Gynoecium stylate. Styles 1; apical. Stigmas 1; capitate. Placentation axile. Ovules (1–)5–50 per locule; ascending, or horizontal; non-arillate; anatropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal. Seeds non-endospermic; winged (the wing unilateral). Cotyledons 2. Embryo straight.
Etymology. In honour of Magnus Lagerstroem (1696–1759), a friend of Linnaeus and benefactor of Uppsala University.
Wheeler, J. R.; Rye, B. L.; Koch, B. L.; Wilson, A. J. G.; Western Australian Herbarium (1992). Flora of the Kimberley region. Western Australian Herbarium. Como, W.A.
Australia. Bureau of Flora and Fauna (1990). Flora of Australia. Volume 18, Podostemaceae to Combretaceae. Australian Govt. Pub. Service. Canberra.
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