The families of flowering plants
Habit and leaf form. Lianas (usually), or shrubs. Plants green and photosynthesizing. Climbing (usually), or self supporting (less often). Leaves alternate; herbaceous, or leathery; petiolate; non-sheathing; with minute, obscure reddish gland-dots, cf. Myrsinaceae; simple. Lamina entire; pinnately veined (the laterals usually arcuate-anastomosing). Leaves exstipulate. Lamina margins entire (usually cartilaginous).
Leaf anatomy. The leaf lamina dorsiventral. Stomata present; mainly confined to one surface (abaxial); anomocytic, or paracytic. Hairs present (records include simple unicellular, uniseriate hairs, and glandular forms with uniseriate stalks and heads of one or more cells). Lamina without secretory cavities. The mesophyll containing crystals. The crystals druses.
Axial (stem, wood) anatomy. Secretory cavities absent. Cork cambium present; initially superficial. 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 medium; exclusively solitary. The vessel end-walls simple, or scalariform and simple (in different species). The vessels without vestured pits; without spiral thickening. The axial xylem with tracheids, or without tracheids (?); without vasicentric tracheids; with fibre tracheids; without libriform fibres; including septate fibres, or without septate fibres. The fibres without spiral thickening. The parenchyma very sparse or absent. Included phloem absent. The wood not storied.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in cymes, or in racemes, or in panicles. Inflorescences axillary; usually few- to many-flowered pedunculate cymes, rarely a small panicle or a simple raceme. Flowers minute, or small; regular; (4–)5(–6) merous; cyclic; tetracyclic. Hypogynous disk present; intrastaminal; annular (or cupular), or of separate members (the lobes sometimes bearing indurated, more or less discoid glands).
Perianth with distinct calyx and corolla; (8–)10(–12); 2 whorled; isomerous. Calyx (4–)5; 1 whorled; polysepalous; imbricate. Corolla (4–)5(–6); 1 whorled; opposite the calyx; polypetalous (the petals opposite the sepals, larger); imbricate; fleshy, or not fleshy.
Androecium (4–)5(–6). Androecial members adnate (to the bases of the petals); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens (4–)5(–6); isomerous with the perianth; oppositisepalous (but also opposite the petals, which are themselves opposite the sepals); alternating with the corolla members. Anthers extrorse, or introrse. Anther wall initially with more than one middle layer (2). Tapetum glandular. Pollen grains aperturate; 3 aperturate; colporate (to colporoidate).
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary 2 locular. Gynoecium stylate. Styles 2; partially joined (erect, more or less coherent); apical to lateral. Stigmas 2 (simple). Placentation axile to apical. Ovules 2 per locule; horizontal to ascending; more or less apotropous; with ventral raphe; collateral, or superposed; hemianatropous; unitegmic (the single integument not covering the dome-shaped nucellus, so forming no micropyle); crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Endosperm formation helobial. Endosperm haustoria present; chalazal.
Fruit fleshy (with crustaceous, conspicuously sculptured or pitted endocarp); indehiscent, or a schizocarp. Mericarps when schizocarpic, 2; comprising drupelets (flattened, dorsally gibbous drupaceous carpels, their styles becoming adaxially subbasal and persisting as a beak on each carpel). Fruit if non-schizocarpic, a drupe. Seeds non-endospermic. Cotyledons 2 (oily).
Seedling. Germination phanerocotylar.
Physiology, phytochemistry. Not cyanogenic. Iridoids not detected. Proanthocyanidins present. Flavonols present; quercetin, or kaempferol and quercetin (?). Aluminium accumulation not found.
Geography, cytology. Paleotropical. Sub-tropical to tropical. India and Eastern Asia to the Solomons. 2n = 24.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rosiflorae (? tentatively re-assigned from Rutiflorae, cf. Chase et al 1993); near Hamamelidales (?). Cronquists Subclass Magnoliidae; Ranunculales. APG III core angiosperms; peripheral eudicot; cf. Superorder Proteanae. APG IV Order Sabiales.
Species 55. Genera 1; only genus, Sabia.
General remarks. Sabia seems distinguishable from Meliosmaceae (q.v.) only by the regular flowers and the androecium comprising (4-)5(-6) stamens with no staminodes.
Illustrations. • Sabia latifolia: Bot. Mag. 146 (1920). • Sabia swinhoei, as S. gracilis: Hook. Ic. Pl. 29 (1907).
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: 15th April 2018. delta-intkey.com/angio’.