The families of flowering plants.
Habit and leaf form. Lianas.Climbing. Leaves opposite; foetid (e.g.Congea), or without marked odour (?); simple. Lamina entire. Leaves exstipulate. Lamina margins entire, or serrate, or dentate.
Leaf anatomy. Hairs present. Complex hairs present, or absent; sometimes stellate.
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in heads, or in panicles, or in heads and in panicles. The ultimate inflorescence unit cymose. Inflorescences 3–7(–9) flowered capitate cymes, often aggregated into large terminal panicles; with involucral bracts (each cyme with an involucre of six equal, coloured, more or less membranous, accrescent members comprising two bracts and four bracteoles).Flowers bracteate; bi- bracteolate; very irregular; zygomorphic.
Perianth with distinct calyx and corolla; (8–)10(–16); 2 whorled; isomerous, or anisomerous. Calyx (4–)5(–8); 1 whorled; gamosepalous; persistent; more or less accrescent (or inflating); valvate (scarcely), or open in bud. Corolla 5–16; 1 whorled; gamopetalous; imbricate; unequal but not bilabiate, or bilabiate, or regular.
Androecium 4–16. Androecial members adnate (epipetalous); free of one another; 1 whorled. Stamens 4–16; oppositisepalous; alternating with the corolla members. Anthers tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. Anther wall of the ‘dicot’ type. Tapetum glandular. Pollen grains aperturate; 3 aperturate; colpate, or colporate; 2-celled.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil imperfectly 4 celled, or 1 celled (above). Gynoecium syncarpous; synstylovarious; superior. Ovary 2 locular (morphologically), or 1 locular (above).Locules partially secondarily divided by ‘false septa’. Gynoecium stylate. Styles 1 (the style filiform, shortly bifid); from a depression at the top of the ovary (?). Stigmas 2. Placentation free central. Ovules in the single cavity 4; pendulous; anatropous; unitegmic; tenuinucellate. Endosperm formation cellular. Embryogeny onagrad.
Fruit non-fleshy; indehiscent; a drupe (included in the accrescent calyx); 1–4 seeded. Seeds non-endospermic. Embryo straight.
Geography, cytology. Tropical. Tropical America, Africa, Asia.
Taxonomy.Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Lamiiflorae; Lamiales. Cronquist’s Subclass Asteridae; Lamiales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Lamiales (as a synonym of Labiatae).
Species 34. Genera 3; Symphorema, Sphenodesme, Congea.
General remarks. These genera are part of the Labiatae/Verbenaceae problem (see remarks under Labiatae), and this description is inadequate.