Habit and leaf form. Small trees, or shrubs (mangroves, with the habit of Rhizophora). Helophytic. Leaves alternate; leathery; non-sheathing; gland-dotted (punctate); simple. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire.
Leaf anatomy. Lamina dorsiventral; with secretory cavities. Secretory cavities schizogenous (with yellow or reddish brown contents).
Stem anatomy. Secretory cavities present (schizogenous, with yellow or reddish-brown contents). Cork cambium present; initially superficial. Secondary thickening developing from a conventional cambial ring. Vessel end-walls simple. Wood parenchyma paratracheal.
Reproductive type, pollination. Hermaphrodite; plants viviparous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in `inflorescences'; in racemes, or in umbels. Inflorescences terminal, or axillary; sessile terminal or axillary umbels, or short branched racemes. Flowers ebracteate; ebracteolate; small; somewhat irregular to very irregular; asymmetric. The floral asymmetry involving the perianth (the calyx). Flowers 5 merous; cyclic; tetracyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous (leathery); unequal but not bilabiate; dextrorsely contorted. Corolla 5; 1 whorled; gamopetalous (shortly tubular); dextrorsely contorted; more or less regular (the lobes soon reflexing); leathery.
Androecium 5. Androecial members adnate (inserted in the hairy corolla tube); coherent (the filaments shortly connate); 1 - adelphous; 1 - whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; alternisepalous. Anthers dehiscing via longitudinal slits; introrse; bilocular (the loculi internally transversely septate); tetrasporangiate.
Gynoecium 3-5. Carpels reduced in number relative to the perianth to isomerous with the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 1 locular. Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1. Placentation free central. Ovules in the single cavity 30-100 (`many'); horizontal to ascending; anatropous; unitegmic; crassinucellate. Endosperm formation nuclear (but with subsequent centripetal wall formation). Endosperm haustoria present; from secondary endosperm tissue, invading funicle and integument.
Fruit non-fleshy; ultimately dehiscent; a capsule to capsular-indehiscent (cylindrical, arcuate, longitudinally ribbed); 1 seeded. Seeds non-endospermic. Embryo well differentiated (germinating within the pericarp). Cotyledons connate into a tube enclosing the plumule. Embryo bent (cylindrical).
Physiology, biochemistry. Not cyanogenic. Iridoids absent. Proanthocyanidins present. Saponins/sapogenins present. Anatomy non-C4 type.
Peculiar feature. Mangroves.
Geography, cytology. Paleotropical and Australian. Tropical. Palaeotropical.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren's Superorder Primuliflorae; Primulales. Cronquist's Subclass Dilleniidae; Primulales. Takhtajan's Subclass Dilleniidae; Ericanae; Ebenales. Species 2. Genera 1; Aegiceras.