The families of flowering plants
Habit and leaf form. Trees, or shrubs; 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. Leaf development not graminaceous.
General anatomy. Plants with crystal sand (in the pith mesophyll of young leaves), or without crystal sand. Plants with silica bodies, or without silica bodies.
Leaf anatomy. The leaf lamina dorsiventral (with several palisade layers). Stomata present; mainly confined to one surface (abaxial, protected by beak-like extensions from guard or subsidiary cells); paracytic. Hairs present; exclusively eglandular; not 2-armed, unicellular (frequently forming a felt abaxially). Adaxial hypodermis present (often), or absent. Lamina without secretory cavities. The mesophyll with sclerenchymatous idioblasts (supporting the palisades). Minor leaf veins without phloem transfer cells.
Axial (stem, wood) anatomy. Young stems tetragonal (the twigs 4-angled). Secretory cavities absent. Cork cambium present; initially superficial. Nodes tri-lacunar. Primary vascular tissues in a cylinder, without separate bundles, or comprising a ring of bundles; collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays fairly wide.
The wood diffuse porous. The vessels very small; exclusively solitary. The vessel end-walls oblique; scalariform (with few bars). The vessels without vestured pits; with spiral thickening. The axial xylem with tracheids; with fibre tracheids; without libriform fibres. The fibres with spiral thickening, or without spiral thickening. The parenchyma apotracheal (scattered among the fibres, sometimes tending to form short uniseriate lines). Included phloem absent. The wood not storied.
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 (13 in each bract axil); ebracteolate; small; (male) regular; (male) 4 merous; cyclic. Free hypanthium absent.
Perianth sepaline (of bractlike tepals, in the male flowers), or vestigial to absent (absent or in the form of 24 small appendages at the top of the gynoecium beneath the styles, in female flowers); 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, phytochemistry. Sugars transported as sugar alcohols + oligosaccharides + sucrose. Not cyanogenic. Alkaloids present (toxic). Verbascosides not detected. Iridoids detected (notably aucubin); Route II type (normal and decarb.). Saponins/sapogenins absent. Proanthocyanidins absent. Flavonols absent. Ellagic acid absent (one species). Aluminium accumulation not found.
Geography, cytology. Holarctic and Neotropical. Sub-tropical. Southeast U.S.A., Central America and West Indies. X = 11.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgrens Superorder Corniflorae; Cornales. Cronquists Subclass Rosidae; Cornales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Garryales.
Species 18. Genera 1; only genus: Garrya.
Illustrations. • Technical details: Garrya. • Garrya elliptica: Bot. Reg. 1686, 1835. • Garrya fadyenii: Hook. Ic. Pl. 4 (1841).
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: 20th July 2017. delta-intkey.com/angio’.