Gerrardinaceae M.H. Alford
Habit and leaf form. Small trees, or shrubs (sometimes scandent). Self supporting, or climbing; when climbing, merely scrambling. Mesophytic. Leaves alternate; flat; not gland-dotted; simple. Lamina entire; pinnately veined. Leaves stipulate. Lamina margins serrate (or double serrate; teeth cunonioid, i.e. with a branching vein extending to the sinus and the tooth apex, the apex glandular but non-spherical and non-torus-shaped); flat.
Leaf anatomy. Epidermis without crystal idioblasts. Mucilaginous epidermis present.
The mesophyll containing calcium oxalate crystals. The mesophyll crystals druses.
Reproductive type, pollination. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the disk.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes (raceme-like, few-flowered). Inflorescences axillary. Flowers regular; 5 merous; tetracyclic. Free hypanthium present. Hypogynous disk present; intrastaminal (lobed between the stamens); annular.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; persistent; imbricate. Corolla 5; 1 whorled; polypetalous; regular; deciduous. Petals sessile; entire.
Androecium 5. Androecial members free of the perianth; all equal; free of one another; 1 whorled. Stamens 5; isomerous with the perianth; alternisepalous; opposite the corolla members. Anthers basifixed; dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; eu-syncarpous; superior, or partly inferior (apparently due to being recessed in receptacle). Ovary 1 locular; sessile. Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1 (-2); 2 lobed (obscurely); capitate (or subcapitate, obscurely 2-lobed). Placentation apical. Ovules in the single cavity 4; pendulous; anatropous.
Fruit fleshy, or non-fleshy; indehiscent; a berry (sometimes dry). Seeds endospermic (?). Testa smooth.
Physiology, biochemistry. Not cyanogenic.
Geography, cytology. Paleotropical, or Cape. Sub-tropical, or tropical. Southern and eastern Africa.
Taxonomy. Subclass Dicotyledonae; Crassinucelli (? - referred tentatively, cf. Flacourtiaceae). Dahlgren’s Superorder Violiflorae; Violales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Huertiales.
Species 2. Genera 1; Gerradina.
Alford 2006, Taxon 55, 959–964. Formerly in Flacourtiaceae but differing from the generally similar tribe Homalieae by apical placentation, small embryo, cunonioid leaf teeth and introrse anthers. Not placed in a molecular analysis except in Eurosids II near Sapindales but with poor support. It was considered incertae sedis at the level of Order. The description is inadequate at present. Wood anatomy, embryology, cytology and chemistry have not been studied.
Miscellaneous. Description encoded by T.D. Macfarlane, March 2009.