Habit and leaf form. Shrubs. Young stems tetragonal to cylindrical. Helophytic, or mesophytic, or xerophytic. Leaves opposite; decussate; leathery; petiolate; connate (via the stipules), or not connate; gland-dotted, or not gland-dotted; simple; epulvinate. Leaf blades entire; pinnately veined; cross-venulate. Leaves with stipules. Stipules interpetiolar (connate into a truncate sheath); with colleters (secreting mucilage), or without colleters. Leaf blade margins entire. Leaves without a persistent basal meristem. Domatia not recorded (absent). Stem anatomy. Nodes unilacunar, or tri-lacunar. Secondary thickening developing from a conventional cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants homostylous, or heterostylous. Entomophilous. Pollination mechanism conspicuously specialized (with passive pollen presentation involving stylar modification), or unspecialized.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescence many-flowered. Flowers in cymes. Inflorescences compound. The terminal inflorescence unit cymose. Inflorescences supra-axillary; shortly pedunculate. Flowers small; regular; 4 merous, or 5 merous; cyclic; tetracyclic. Free hypanthium present, or absent (depending on interpretation); turbinate, ribbed. Perianth with distinct calyx and corolla; 8, or 10; 2 -whorled; the two whorls isomerous. Calyx 4, or 5; 1 -whorled; gamosepalous; entire, or lobed; open in bud; regular; persistent. Corolla 4, or 5; 1 -whorled; gamopetalous; contorted; tubular; regular; white. Androecium 4, or 5. Androecial members adnate (to the corolla tube); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4, or 5. Staminal insertion in the throat of the corolla tube. Stamens becoming exserted; isomerous with the perianth; oppositisepalous. Anthers sagittate at base; dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen shed in aggregates, or shed as single grains; if aggregated, in tetrads. Gynoecium 2 carpelled. The pistil 2 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious to eu-syncarpous; inferior. Ovary plurilocular; 2 locular. Gynoecium transverse. Epigynous disk present. Gynoecium stylate. Styles 1; forked; attenuate from the ovary, or from a depression at the top of the ovary; apical; shorter than the ovary at anthesis to much longer than the ovary at anthesis; becoming exserted (prominently). Stigmas 1; 2 - lobed (stigmatic branches white); wet type, or dry type; papillate, or non-papillate; Group II type and Group IV type. Placentation axile. Ovules 2 per locule; pendulous, or horizontal, or ascending; anatropous, or hemianatropous.
Fruit and seed features. Fruit fleshy, or non-fleshy (? endocarp hard); indehiscent; a drupe (8-ribbed). The drupes with separable pyrenes (4 single-seeded cells). Fruit 4 seeded. Seeds endospermic, or non-endospermic. Endosperm ruminate, or not ruminate; if present, oily. Cotyledons 2. Embryo straight, or curved. Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Aluminium accumulation demonstrated, or not found.
Special features. Mangroves.
Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province.
Additional characters Corolla lobes spreading.