Family Symplocaceae
Symplocaceae Desf.Habit and leaf form. Trees and shrubs; non-laticiferous and without coloured juice. 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; without a persistent basal meristem. Leaf anatomy. Stomata present; mainly confined to one surface (abaxial); generally paracytic. Lamina dorsiventral (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). Stem anatomy. Cork cambium present; initially superficial. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring. Xylem with tracheids; with vessels. Vessel end-walls scalariform. Wood parenchyma apotracheal. 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 unit 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 (sometimes in bundles); when bundled 1 adelphous, or 5 adelphous, or 10 adelphous (? — the bundles alternating with the corolla lobes); 1–4 whorled. The androecial bundles when bundled, 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 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; without fleshy investment. 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, biochemistry. Not cyanogenic. Alkaloids present, or absent (usually). Iridoids detected; ‘Route I’ type (normal). Proanthocyanidins present; cyanidin and delphinidin. Flavonols present; quercetin. Ellagic acid absent (Symplocos). Saponins/sapogenins present. Aluminium accumulation demonstrated (by all?). 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. |
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