Family Garryaceae
Garryaceae Lindl.Excluding Aucubaceae Habit and leaf form. Trees, or shrubs. Plants non-succulent. Leptocaul. Mesophytic. Leaves evergreen; opposite; flat; leathery; petiolate; connate (with the petioles united at the base); simple; epulvinate. Lamina somewhat dissected, or entire; sometimes somewhat pinnatifid; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire; flat. Leaves without a persistent basal meristem. General anatomy. Plants with ‘crystal sand’, or without ‘crystal sand’. Leaf anatomy. Stomata present; paracytic. Lamina dorsiventral. The mesophyll with sclerencymatous idioblasts. Minor leaf veins without phloem transfer cells. Stem anatomy. Young stems tetragonal (the twigs 4-angled). Cork cambium present; initially superficial. Nodes tri-lacunar. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with tracheids; with vessels. Vessel end-walls oblique; scalariform. Reproductive type, pollination. Plants dioecious. Gynoecium of male flowers vestigial. Pollination anemophilous. Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in catkins. Inflorescences axillary; pendulous and silky hairy, unisexual aments, the flowers long stalked in the males and sessile in the females. Flowers bracteate (1–3 in each bract axil); ebracteolate; small; (male) regular; (male) 4 merous; cyclic. Free hypanthium absent. Perianth sepaline (bractlike tepals, in the male flowers), or vestigial to absent (absent or in the form of 2–4 small appendages at the top of the gynoecium beneath the styles, in females); 2(–4) (when present in female flowers), or 4 (male flowers); 1 whorled. Calyx 2(–4) (when present, in female flowers), or 4 (in male flowers); 1 whorled; polysepalous, or gamosepalous (in the sense of being usually apically connate in the male flowers, with the stamens protruding from between them below); in male flowers, regular; in male flowers valvate. Androecium in male flowers, 4. Androecial members free of the perianth; all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 4; isomerous with the perianth; alternisepalous (i.e. alternating with the ‘tepals’). Anthers basifixed; non-versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium probably developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with one middle layer. Tapetum amoeboid. Pollen shed as single grains. Pollen grains aperturate; 2–3(–15) aperturate; colporate; 2-celled. Gynoecium 2(–3) carpelled. The pistil 1 celled. Gynoecium syncarpous; synovarious; supposedly inferior (though this has been contentious in the past). Ovary 1 locular. Epigynous disk absent. Gynoecium stylate. Styles 2(–3); free; apical. Stigmas dry type; non-papillate; Group II type. Placentation apical. Ovules in the single cavity 2(–3); funicled; pendulous; apotropous; with dorsal raphe (the micropyle towards the placenta); arillate (in that an obturator from the placenta occludes the upper part of the locule); anatropous; unitegmic; crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; proliferating. Endosperm formation nuclear. Embryogeny solanad. Fruit fleshy to non-fleshy; indehiscent; a berry (long persistent, becoming dry and thin walled, crowned by the persistent styles); 1(–2) seeded. Seeds endospermic. Endosperm oily (with petroselinic acid). Embryo well differentiated (small). Cotyledons 2. Embryo straight. Seedling. Germination phanerocotylar. Physiology, biochemistry. Not cyanogenic. Alkaloids present (toxic). Iridoids detected (notably aucubin); ‘Route II’ type (normal and decarb.). Verbascosides not detected. Proanthocyanidins absent. Flavonols absent. Ellagic acid absent (one species). Saponins/sapogenins absent. Aluminium accumulation not found. Sugars transported as sugar alcohols + oligosaccharides + sucrose. Geography, cytology. Holarctic and Neotropical. Sub-tropical. Southeast U.S.A., Central America and West Indies. X = 11. Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Corniflorae; Cornales. Cronquist’s Subclass Rosidae; Cornales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Garryales. Species 18. Genera 1; only genus: Garrya. Illustrations. |
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