The families of flowering plants
Habit and leaf form. Trees and shrubs; with coloured juice. Mesophytic, or xerophytic. Leaves alternate; petiolate; non-sheathing; gland-dotted, or not gland-dotted; aromatic, or without marked odour; simple. Lamina dissected; palmatifid; palmately veined; cross-venulate. Leaves stipulate. Lamina margins serrate. Leaf development not graminaceous.
Leaf anatomy. Mucilaginous epidermis often present. Stomata mainly confined to one surface (adaxial), or on both surfaces. Hairs present (mostly long, simple and multicellular, sometimes also peltate). The mesophyll commonly with yellow or reddish resinous contents; containing crystals. The crystals druses. Minor leaf veins without phloem transfer cells (Cochlosperma).
Axial (stem, wood) anatomy. Secretory cavities present (in the cortex and pith), or absent; with mucilage. Primary vascular tissues in a cylinder, without separate bundles to comprising a ring of bundles (with the phloem traversed by the widening ends of the medullary rays); collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring.
The wood diffuse porous. The vessels medium to large; solitary, radially paired, and in radial multiples. The vessel end-walls scalariform. The vessels without vestured pits; without spiral thickening. The axial xylem with fibre tracheids; without septate fibres. The fibres without spiral thickening. The parenchyma predominantly apotracheal. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones. Included phloem absent. The wood partially storied (VPI), or not storied. Tyloses present (often common).
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in panicles and in racemes. Inflorescences paniculate or racemose. Flowers large; regular to somewhat irregular. Free hypanthium absent.
Perianth with distinct calyx and corolla; 8, or 10; 2 whorled; isomerous. Calyx 4, or 5; 1 whorled; polysepalous; not persistent (deciduous); imbricate. Corolla 4, or 5; 1 whorled; polypetalous; imbricate, or contorted; yellow.
Androecium 15–100 (many). Androecial members branched (with trunk bundles); maturing centrifugally; free of the perianth; all equal to markedly unequal; free of one another. Androecium exclusively of fertile stamens. Stamens 15–60; polystemonous. Anthers dehiscing via pores (these apical, often confluent). Pollen grains aperturate; 3 aperturate; colporate; 2-celled.
Gynoecium 3–5 carpelled. The pistil 1 celled, or 3 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 1 locular, or 3 locular. Styles 1; attenuate from the ovary; apical. Stigmas 1 (minute). Placentation when unilocular, parietal; when trilocular, axile. Ovules in the single cavity when unilocular, 20–100 (i.e. many); when trilocular, 20–50 per locule (i.e. many); anatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Endosperm formation nuclear.
Fruit non-fleshy; dehiscent; a capsule. Capsules three to five valvular. Seeds endospermic. Endosperm oily. Cotyledons 2. Embryo straight, or curved, or coiled. Micropyle zigzag.
Seedling. Germination phanerocotylar.
Physiology, phytochemistry. Saponins/sapogenins present. Proanthocyanidins present; cyanidin. Flavonols present; kaempferol, quercetin, and myricetin. Ellagic acid present (Cochlospermum). Aluminium accumulation not found.
Geography, cytology. Tropical. Widespread-tropical, except Malaysia.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Malviflorae; Malvales. Cronquists Subclass Dilleniidae; Violales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Malvales (as a synonym of Bixaceae?).
Species 20–25. Genera 2; Amoreuxia, Cochlospermum.
General remarks. Intkey comparisons of these compiled descriptions depict 10 differences from Bixaceae (q.v.), involving leaf form and anatomy, wood anatomy, floral, fruit and seed details, and phytochemistry.
Illustrations. • Technical details: Cochlospermum (Hutchinson).
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 June 2017. delta-intkey.com/angio’.