Family Alseuosmiaceae

Alseuosmiaceae Airy Shaw

Habit and leaf form. Shrubs (often of pittosporaceous appearance). Plants non-succulent. Leaves alternate (to sub-opposite), or whorled (pseudowhorls of 3, 4 or 5); when alternate, spiral; not gland-dotted; simple. Lamina entire. Leaves exstipulate. Lamina margins sinuous dentate, or entire.

Leaf anatomy. Stomata present; anomocytic.

Stem anatomy. Cork cambium present; initially superficial. Secondary thickening developing from a conventional cambial ring. Xylem with tracheids. Vessel end-walls scalariform, or scalariform and simple. Wood ring porous.

Reproductive type, pollination. Plants hermaphrodite, or polygamomonoecious (? — ‘polygamous’). Floral nectaries present. Nectar secretion from the disk.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’ (axillary and solitary or fasciculate, rarely in racemes or subterminal); when solitary, (sub) terminal, or axillary; when aggregated, in racemes, or in fascicles. Inflorescences (sub) terminal, or axillary. Flowers sometimes fragrant; regular; (4–)5(–7) merous. Free hypanthium present, or absent.

Perianth with distinct calyx and corolla; 8–14; 2 whorled; isomerous. Calyx (4–)5(–7); 1 whorled; polysepalous; valvate, or open in bud. Corolla (4–)5(–7); 1 whorled; gamopetalous; valvate; urceolate, or funnel-shaped.

Androecium (4–)5(–7). Androecial members free of the perianth, or adnate (to the corolla tube); all equal, or markedly unequal (two sometimes larger); free of one another. Androecium exclusively of fertile stamens. Stamens (4–)5(–7); isomerous with the perianth; oppositisepalous. Anthers dorsifixed; non-versatile; dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 3 aperturate; colporate.

Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; eu-syncarpous; partly inferior to inferior. Ovary 2 locular. Epigynous disk present (flat or tumid, crowning the ovary). Gynoecium stylate. Styles 1; apical. Stigmas 1; more or less 2 lobed; clavate, or capitate. Placentation axile. Ovules 1–50 per locule (to ‘many’). Antipodal cells formed; 3; not proliferating.

Fruit fleshy; indehiscent; a berry. Dispersal unit the fruit. Seeds endospermic. Cotyledons 2.

Physiology, biochemistry. Iridoids not detected (S.R. Jensen, unpublished).

Geography, cytology. Paleotropical and Antarctic. Frigid zone and tropical. New Caledonia, New Zealand.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli (?). Dahlgren’s Superorder Corniflorae; Cornales. Cronquist’s Subclass Rosidae; Rosales. APG (1998) Eudicot; core Eudicot; Asterid; Euasterid II. APG 3 (2009) Order: Asterales.

Species 11. Genera 3; Alseuosmia (Periomphale, Memecylanthus), Crispiloba, Wittsteinia.

Support our developers