The families of flowering plants
Habit and leaf form. Trees, or shrubs (sometimes spinose, with axillary spines). Self supporting, or climbing; when scandent, scrambling. Xerophytic (of hot, dry, often coastal or saline regions). Leaves opposite; somewhat fleshy, or herbaceous, or leathery (usually olive grey); shortly petiolate; simple. Lamina entire. Leaves stipulate (often, but the stipules rudimentary), or exstipulate (?). Lamina margins entire.
Leaf anatomy. The leaf lamina dorsiventral (in Azima), or bifacial. Stomata present; anomocytic, or anisocytic, or paracytic. Adaxial hypodermis present, or absent. The mesophyll containing crystals, or without crystals (? - with crystalline inclusions of uncertain chemical composition: Metcalfe and Chalk). The crystals druses. Minor leaf veins without phloem transfer cells (Salvadora).
Axial (stem, wood) anatomy. Cork cambium present; initially superficial. Primary vascular tissues comprising a ring of bundles; collateral. Internal phloem absent. Secondary thickening developing from a conventional cambial ring (?), or anomalous (usually). The anomalous secondary thickening when present, from a single cambial ring. Primary medullary rays wide.
The wood diffuse porous. The vessels tending to be small and medium (with medium sized ones surrounded by small tracheid-like members); in radial multiples and clustered. The vessel end-walls simple. The vessels without spiral thickening. The axial xylem without fibre tracheids; with libriform fibres; without septate fibres. The fibres without spiral thickening. The parenchyma paratracheal (from scanty to vasicentric). Included phloem of the foraminate type present. The wood storied, or partially storied (VPI).
Reproductive type, pollination. Plants hermaphrodite, or dioecious, or polygamomonoecious, or polygamodioecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in fascicles, or in panicles. The ultimate inflorescence units mostly racemose. Inflorescences terminal, or axillary; of various sorts, axillary or terminal, mostly indeterminate. Flowers small; regular; mostly 4 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present, or absent; when present, intrastaminal; when present, of separate members (represented by small glands alternating with the stamens).
Perianth with distinct calyx and corolla; (6–)8(–10); 2 whorled; isomerous to anisomerous. Calyx 2–4(–5); 1 whorled; gamosepalous; blunt-lobed; regular; imbricate, or valvate. Corolla 4(–5); 1 whorled; appendiculate (with teeth or small glands on the inside these representing staminodes?), or not appendiculate; polypetalous, or gamopetalous (shortly connate at the base in Salvadora). Corolla lobes markedly longer than the tube. Corolla imbricate, or contorted; regular.
Androecium 4(–5), or 8(–10). Androecial members adnate, or free of the perianth and adnate; free of one another, or coherent (the stamens connate below into a tube, in Dobera); 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens, or including staminodes (often, if teeth or glands inside the corolla are taken to be staminodal). Staminodes if present, 4(–5). Stamens 4(–5); isomerous with the perianth; oppositisepalous. Anthers dorsifixed; dehiscing via longitudinal slits; bilocular (the loculi back to back); tetrasporangiate; appendaged (via a small, pointed extension of the connective), or unappendaged. Pollen shed as single grains. Pollen grains aperturate; 3 aperturate (usually), or 6 aperturate; colporate (usually tricolporate), or rugate (exceptionally 6-rug(or)oidate).
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled, or 2 celled. Gynoecium syncarpous; synstylovarious, or eu-syncarpous; superior. Ovary 1 locular (Dobera, Salvadora), or 2 locular (Azima). Gynoecium shortly stylate. Styles 1; apical; shorter than the ovary. Stigmas 1, or 2; entire or bilobed. Placentation when unilocular, basal; when bilocular, basal to axile. Ovules in the single cavity 1–2; 1–2 per locule; ascending; apotropous; with ventral raphe; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3 (large); not proliferating. Synergids pear-shaped. Endosperm formation nuclear.
Fruit fleshy; indehiscent; a berry, or a drupe. The drupes with one stone. Fruit mostly 1 seeded. Seeds non-endospermic. Embryo well differentiated. Cotyledons 2; plano-convex, cordate, oily.
Physiology, phytochemistry. C3. C3 physiology recorded directly in Salvadora. Anatomy non-C4 type (Salvadora). Mustard-oils present. Cyanogenic. Alkaloids present, or absent. Iridoids not detected. Proanthocyanidins absent. Flavonols present; quercetin. Ellagic acid absent (Salvadora). Aluminium accumulation not found.
Geography, cytology. Paleotropical. Sub-tropical to tropical. Africa, Madagascaar, Southern Asia, Malaysia. X = 12.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Violiflorae; Salvadorales (or Capparidales). Cronquists Subclass Rosidae; Celastrales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Brassicales.
Species 12. Genera 3; Azima, Dobera, Salvadora.
Economic uses, etc. Toothbrushes consisting of twigs and stems with supposed antibacterial properties are used in Africa and the Middle East, while oils are used to treat rheumatism, and fruits and young shoots have other assorted herbalist applications.
Illustrations. • Dobera loranthifolium, as D. allenii: Hook. Ic. 31 (1915). • Salvadora indica: R. Wight 2 (1850). • Le Maout and Decaisne: Salvadora persica. • Leaf anatomical details of Salvadora persica, Dobera (Platymitium) roxburgii and D. loranthifoium (Solereder, 1908). • Azima tetracantha: R. Wight 2 (1850).
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’.