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The families of flowering plants

L. Watson and M. J. Dallwitz

Symplocaceae Desf.

Habit and leaf form. Trees and shrubs. Mesophytic. Leaves evergreen; alternate; spiral; leathery, or ‘herbaceous’; petiolate; non-sheathing; not gland-dotted; often sweet tasting; simple. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate; leaf development not ‘graminaceous’.

Leaf anatomy. The leaf lamina dorsiventral (these equipped with protruding, unicellular water-secreting structures, swollen and bladderlike to the outside, but constricted below where they enter the leaf through a rosette of epidermal cells). Stomata present; mainly confined to one surface (abaxial); generally paracytic. Lamina without secretory cavities.

Axial (stem, wood) anatomy. Cork cambium present; initially superficial. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring.

The wood diffuse porous. The vessels small; solitary. The vessel end-walls scalariform, or reticulately perforated to scalariform (i.e., occasionally slightly reticulate). The vessels commonly with spiral thickening. The axial xylem with tracheids; without vasicentric tracheids; with fibre tracheids; without libriform fibres; without septate fibres. The fibres often with spiral thickening. The parenchyma apotracheal; wood not storied.

Reproductive type, pollination. Plants hermaphrodite, or polygamomonoecious (rarely). Pollination entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’, or solitary (less often); in racemes, in spikes, and in panicles. The ultimate inflorescence units racemose (usually), or cymose (?). Inflorescences terminal, or axillary; usually racemes, less often panicles ‘etc’. Flowers bracteate; bi- bracteolate; regular; usually 5 merous; cyclic; pentacyclic to polycyclic. Free hypanthium absent.

Perianth with distinct calyx and corolla; 6–8 (rarely), or 10, or 15; 2 whorled, or 3 whorled; isomerous. Calyx (3–)5; 1 whorled; gamosepalous (basally connate); regular; persistent; imbricate, or valvate. Corolla (3–)5, or 10(–11); 1 whorled, or 2 whorled; gamopetalous (the tube short); imbricate; regular.

Androecium (4–)5, or 10, or 15(–100) (i.e. to ‘many’). Androecial members branched, or unbranched; free of the perianth, or adnate (usually attached to the corolla tube); markedly unequal; free of one another, or coherent (i.e., sometimes in bundles); when bundled 1 adelphous, or 5 adelphous, or 10 adelphous (?); 1–4 whorled. The androecial bundles when present, alternating with the corolla members. Androecium exclusively of fertile stamens. Stamens (4–)5, or 10, or 15–35 (or more?); reduced in number relative to the adjacent perianth (rarely), or isomerous with the perianth to polystemonous. Anthers not becoming inverted during development; dehiscing via longitudinal slits. Pollen grains aperturate; 3(–4) aperturate; colporate (the colpi short); 2-celled.

Gynoecium 2–5 carpelled. Carpels isomerous with the perianth, or reduced in number relative to the perianth. The pistil 2–5 celled. Gynoecium syncarpous; eu-syncarpous; inferior (usually), or partly inferior (rarely). Ovary 2–5 locular. Epigynous disk present (often, around the style), or absent (?). Gynoecium stylate. Styles 1; apical. Stigmas 1; capitate (or lobed). Placentation axile. Ovules 2–4 per locule; funicled; pendulous; non-arillate; anatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3 (uninucleate); not proliferating; ephemeral. Synergids elongated or beaked.

Fruit fleshy; indehiscent; a drupe (usually), or a berry. The drupes with one stone (with 2–5 locules). Fruit 2–5 seeded (one per locule). Seeds endospermic. Endosperm oily. Cotyledons 2 (very short). Embryo curved.

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. Not cyanogenic. Alkaloids present, or absent (usually). Iridoids detected; ‘Route I’ type (normal). Saponins/sapogenins present. Proanthocyanidins present; cyanidin and delphinidin. Flavonols present; quercetin. Ellagic acid absent (Symplocos). Aluminium accumulation widely demonstrated (universal?).

Geography, cytology. Sub-tropical to tropical. Widespread tropical and subtropical, absent from Africa. X = 11–14.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Corniflorae; Cornales. Cronquist’s Subclass Dilleniidae; Ebenales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; Order Ericales.

Species 500. Genera 2; Symplocos, Cordyloblaste.

Illustrations. • Technical details: Symplocos (Lindley). • Technical details: Symplocos. • Symplocos sinica (cf. S. paniculata): Bot. Reg. 710, 1823. • Symplocos spicata (cf. S. cochinchinensis): R. Wight 2 (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: 19th October 2016.’.