The families of flowering plants
Habit and leaf form. Trees (720 m tall). Leaves persistent; alternate; somewhat distichous; subcoriacious; petiolate; non-sheathing; normally orientated; simple. Lamina entire; elliptic ovate (of fagacious aspect); pinnately veined; cross-venulate; cuneate at the base, or oblique at the base. Leaves stipulate. Stipules intrapetiolar; caducous. Lamina margins serrate (above).
Axial (stem, wood) anatomy. Cork cambium present. Internal phloem absent. Secondary thickening developing from a conventional cambial ring.
The wood diffuse porous. The vessel end-walls oblique; reticulately perforated and scalariform (with numerous bars). The vessels without vestured pits. The axial xylem with tracheids; without fibre tracheids; without libriform fibres. The parenchyma apotracheal (diffuse). The secondary phloem not stratified. Tile cells absent.
Reproductive type, pollination. Plants dioecious, or polygamodioecious (less commonly). Gynoecium of male flowers vestigial (rarely), or absent. Pollination anemophilous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in catkins. The ultimate inflorescence units cymose (both male and female aments with some cymules on their primary axes. The male cymules borne verticillately in clusters of three, each cluster 13 flowered and subtended by a single bract; the female partial inflorescences solitary, each one-flowered but reduced, as evidenced by each being subtended by one primary bract, plus two secondary bracts with axillary scales). Inflorescences catkinlike, simple or branched, male or female, with partial inflorescences in the form of reduced cymules, the partial inflorescences and individual flowers not readily distinguishable without reference to their vasculature. Flowers bracteate; small.
Perianth vestigial (small, atop the ovary, in female flowers), or absent (in male flowers).
Androecium of male flowers 8–10 (or more?). Androecial members free of one another. Androecium exclusively of fertile stamens. Stamens 8–10 (or more?); shortly filantherous. Anthers basifixed; non-versatile; dehiscing via longitudinal slits; tetrasporangiate; appendaged. The anther appendages apical (short, by extension of the connective). Endothecium developing fibrous thickenings. Anther epidermis persistent. Pollen grains aperturate; 3 aperturate; porate; 2-celled.
Gynoecium 2 carpelled. The pistil 4 celled. Gynoecium syncarpous; synovarious; inferior. Ovary 4 locular. Epigynous disk absent. Gynoecium stylate. Styles 2(–3); free; apical. Stigmas 2(–3) (the styles stigmatic throughout). Placentation axile. Ovules 1 per locule; funicled; pendulous; hemianatropous; unitegmic; crassinucellate.
Fruit somewhat fleshy; indehiscent; a drupe (drupelike, asymmetric, swollen on one side, greenish, mucilaginous). The drupes with one stone (the endocarp very hard, longitudinally furrowed). Fruit 1 seeded (three of the ovules degenerating). Seeds endospermic (the endosperm two-layered). Embryo well differentiated (massive). Cotyledons 2. Embryo straight.
Seedling. Germination cryptocotylar.
Physiology, phytochemistry. Inulin not found.
Geography, cytology. Neotropical. Central Mexico to southern Panama.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rosiflorae; Fagales. Cronquists Subclass Hamamelidae; Fagales. APG III core angiosperms; core eudicot; Superorder Rosanae; fabid. APG IV Order Fagales.
Species 1. Genera 1; only known representative, Ticodendron incognitum.
General remarks. See Gómez-Laurito and Gómez (1991), Tobe (1991), Carlquist (1991).
Illustrations. • Ticodendron incognitum: Gomez-Laurito and Gomez, Ann. Miss. Bot. Gard. 76 (1989).
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’.