Common name. Turnera Family.
Habit and leaf form. Trees (rarely), or shrubs, or herbs. Leaves alternate; spiral; simple. Leaf blades dorsiventral, or isobilateral; dissected, or entire; when dissected, pinnatifid; pinnately veined; cross-venulate. Leaves with stipules (Erblichia), or without stipules (usually, but often with a pair of glands or floral nectaries at the base of the blade). Leaf blade margins serrate, or dentate (the teeth sometimes glandular). Stem anatomy. Secondary thickening developing from a conventional cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants heterostylous. Selfing or entomophilous.
Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, axillary; when aggregated, in racemes. Inflorescences terminal, or axillary, or epiphyllous (10 species of Turnera). Flowers often (bi-) bracteolate; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present; short to tubular. Perianth with distinct calyx and corolla (and sometimes with a membranous corona inserted below the calyx or at the base of the sepals); 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; toothed; imbricate; regular (usually with a hemispherical swelling within); not persistent. Corolla present; 5; 1 -whorled; polypetalous; contorted; regular; yellow, or red; deciduous. Petals clawed. Androecial members definite in number. Androecium 5. Androecial sequence not determinable. Androecial members free of the perianth (but inserted low on the hypanthium); free of one another; 1 -whorled. Androecium exclusively of fertile stamens (but the hypanthium often bearing five extrastaminal glands or protuberances, or (Piriquetia, Erblichia) with a narrow, fringed corona). Stamens 5; attached inside the hypanthium; isomerous with the perianth; oppositisepalous; all alternating with the corolla members. Anthers dehiscing via longitudinal slits; introrse. Gynoecium 3 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synovarious; superior to partly inferior. Ovary unilocular; 1 locular; sessile. Gynoecium stylate. Styles 3 (opposite the placentas); free. Stigmas 3 (fringed); commissural (i.e. aligned with the placentas); dry type; non-papillate; Group II type (a). Placentation parietal. Ovules in the single cavity (3–)25–100 (to ‘many’); funicled; ascending; arillate (with an ostensibly funicular aril); anatropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules valvular (each of the three valves with a median placenta). Seeds copiously endospermic. Endosperm oily. Embryo well differentiated. Cotyledons 2 (planoconvex). Embryo straight. Seedling. Germination phanerocotylar.
Geography, cytology, number of species. X = 7&10. 120 species.