Habit and leaf form. Small trees, or shrubs (scrambling); non-laticiferous and without coloured juice. Leaves alternate; not gland-dotted; simple. Lamina entire. Leaves exstipulate.
Leaf anatomy. Lamina dorsiventral. The mesophyll with sclerencymatous idioblasts.
Stem anatomy. Secretory cavities present (?). Cork cambium present; initially superficial. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring (?). Xylem without tracheids; with libriform fibres. Vessel end-walls simple. Primary medullary rays narrow (wood rays all uniseriate). Wood parenchyma paratracheal.
Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. The ultimate inflorescence unit cymose. Inflorescences terminal, or axillary; many-flowered thyrses. Flowers regular. Free hypanthium absent.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; regular; persistent; accrescent; imbricate. Corolla 5; 1 whorled; polypetalous (the petals narrow); imbricate; regular; deciduous.
Androecium 9–15. Androecial members free of the perianth; coherent (connate below into a more or less broad ring); 1 adelphous. Androecium exclusively of fertile stamens. Stamens 9–15 (the filaments persistent); diplostemonous to triplostemonous. Anthers dorsifixed; versatile (small, deciduous); dehiscing via longitudinal slits; tetrasporangiate. Pollen grains aperturate; 3 aperturate; colpate, or colporate (colporoidate).
Gynoecium (2–)3 carpelled. Carpels reduced in number relative to the perianth. The pistil (2–)3 celled. Gynoecium syncarpous; synovarious, or synstylovarious, or eu-syncarpous (the single style shortly 3-lobed at the apex, with three short, reflexed styles, or intermediate); superior. Ovary (2–)3 locular. Gynoecium stylate. Styles 1, or 3; when three, free to partially joined; apical. Placentation axile. Ovules 2–50 per locule (to ‘many’); pendulous; anatropous; bitegmic.
Fruit non-fleshy; indehiscent; capsular-indehiscent (thick walled, surrounded by the persistent staminal filaments and winged by the accrescent, leathery or membranous calyx). Dispersal unit the flower (i.e. its remains). Fruit 2–50 seeded (to ‘many’). Seeds non-endospermic.
Geography, cytology. Paleotropical. Tropical. Madagascar.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Theiflorae (by inference); Theales. Cronquist’s Subclass Dilleniidae; Theales. APG (1998) Eudicot; core Eudicot; neither Rosid nor Asterid. APG 3 (2009) Order: Caryophyllales.
Species 7. Genera 1; only genus, Asteropeia.