The families of flowering plants

L. Watson and M.J. Dallwitz

Symphoremataceae Van Tiegh.

~ Verbenaceae, Labiatae.

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.

Axial (stem, wood) anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring.

The axial xylem including septate fibres. ‘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 units 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; inflating or more or less accrescent; 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 III core angiosperms; core eudicot; Superorder Asteranae; lamiid. APG IV Order Lamiales (as a synonym of Labiatae).

Species 34. Genera 3; Symphorema, Sphenodesme, Congea.

General remarks. These genera are part of the Labiatae/Verbenaceae imbroglio (see remarks under Labiatae), and this description is inadequate. The present compilation of data has them differing from Labiatae sensu stric to (q.v.) only in the involucral bracts, pendulous ovules and indehiscent fruits; and from Verbenaceae sensu stricto only in the synstylovarious gynoecium.

Illustrations. • Symphorema involucrata: R. Wight, Ic. Pl. Indiae Orientalis 2 (1843). • Symphorema polyandra: Wight’s Figs. of Indian Plants 2 (1843). • Sphenodesme ferruginea: Wight’s Figs. of Indian Plants 4 (1850).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 5th March 2018.’.