The families of flowering plants
Habit and leaf form. Trees, or shrubs. Switch-plants; with the principal photosynthesizing function transferred to stems (almost leafless, with stiff, spine-tipped branches). Leaves much reduced. Xerophytic. Leaves early deciduous; minute; alternate; membranous (scalelike); simple; exstipulate.
Axial (stem, wood) anatomy. Secretory cavities present (in the phloem); with resin. Cork cambium present (pericyclic); initially deep-seated. Primary vascular tissues comprising a ring of bundles (these separated by the relatively broad medullary rays); collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays wide (with slightly widened distal ends).
The wood ring porous. The vessels solitary (and small). The vessel end-walls simple. The vessels without vestured pits; in the late wood with spiral thickening. The axial xylem with tracheids; with fibre tracheids; without libriform fibres; without septate fibres. The fibres with spiral thickening, or without spiral thickening. The parenchyma apotracheal. The secondary phloem not stratified. Included phloem absent. The wood not storied.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in racemes. The ultimate inflorescence units racemose. Inflorescences axillary; very short axillary racemes. Flowers bracteate (the bracts minute); regular; 4 merous; cyclic. Floral receptacle developing a gynophore (the ovary shortly stipitate). Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla; 8. Calyx 4; 2 whorled (K 2+2 decussate, C 4 diagonal, cf. Cruciferae?); polysepalous (the sepals small); regular; imbricate. Corolla 4; 1 whorled; polypetalous; imbricate; regular; white; deciduous. Petals clawed.
Androecium 8. Androecial members free of the perianth; free of one another. Androecium exclusively of fertile stamens. Stamens 8; diplostemonous; filantherous. Anthers dehiscing via longitudinal slits; introrse; apiculate. Pollen grains aperturate; (2–)3(–4) aperturate; colporate.
Gynoecium 2–5 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 2 locular. Locules without false septa. Gynoecium stylate. Styles 1 (subulate, persistent); apical. Placentation axile. Ovules 5–50 per locule (several to many); anatropous.
Fruit fleshy; indehiscent; a berry. Seeds scantily endospermic. Embryo well differentiated. Cotyledons 2. Embryo much curved.
Physiology, phytochemistry. Mustard-oils present, or absent (?).
Geography, cytology. Holarctic and Neotropical. Southern U.S.A., Mexico.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rutiflorae; Sapindales. Cronquists Subclass Dilleniidae; Capparales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Brassicales.
Species 1 (Koeberlinia spinosa). Genera 1; only genus, Koeberlinia.
General remarks. Description inadequate, e.g. regarding floral morphology, mustard oils.
Illustrations. • Koeberlinia spinosa: Nat. Pflanzenfam. III (1895). • Koeberlinia spinosa (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 February 2018. delta-intkey.com/angio’.