The families of flowering plants
Habit and leaf form. Small trees, or shrubs (with mucilage cells in the cortex). Leaves evergreen; alternate; leathery; petiolate; non-sheathing; simple. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire. Vegetative buds scaly.
Leaf anatomy. Mucilaginous epidermis present. Stomata present; mainly confined to one surface (abaxial); paracytic.
Lamina dorsiventral; without secretory cavities. The mesophyll containing calcium oxalate crystals. The mesophyll crystals druses and solitary-prismatic.
Stem anatomy. Cork cambium present; initially superficial. Cortical bundles absent. Medullary bundles absent. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. Included phloem absent. Xylem with tracheids. Vessel end-walls oblique; scalariform. Primary medullary rays mixed wide and narrow. Wood parenchyma apotracheal (diffuse).
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in racemes. The ultimate inflorescence unit racemose. Inflorescences terminal and axillary, or intercalary (somewhat); racemes, often with sterile, leafy tips. Flowers (bi-) bracteolate (the persistent bracteoles appressed to the calyx); small; regular; 5 merous (throughout); cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; regular; persistent; imbricate. Epicalyx absent (but the calyx closely associated with the bracteoles). Corolla 5; 1 whorled; polypetalous; imbricate; regular.
Androecium 5. Androecial members free of the perianth; all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous (equalling ir shorter than the petals); alternating with the corolla members; inflexed in bud (later erect); filantherous (the filaments thickened and expanded, especially towards the middle, tapering to their tips, the anthers short). Anthers basifixed; non-versatile; dehiscing via pores (each theca with a terminal pore, opening via a small valve); bilocular (the thecae distinct). Pollen shed as single grains. Pollen grains aperturate; 3 aperturate; colporate (to colporoidate).
Gynoecium 5 carpelled. Carpels isomerous with the perianth. The pistil 5 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 5 locular. Gynoecium stylate. Styles 1; apical; short, stout, persistent. Stigmas 1 (lobed), or 5; if considered one, 5 lobed. Placentation axile to apical. Ovules 2 per locule; pendulous; apotropous (Engler); collateral; somewhat campylotropous, or anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle.
Fruit non-fleshy; partly or fully dehiscent; a capsule (rather woody, with a persistent central axis, cf. Theaceae-Theoideae); without fleshy investment. Capsules loculicidal (to halfway or all the way down, the long-persistent valves with a median septum). Seeds scantily endospermic; more or less winged. Embryo well differentiated. Cotyledons 2. Embryo curved (horseshoe-shaped).
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Aluminium accumulation demonstrated.
Geography, cytology. Paleotropical. Tropical. South China to Malay Peninsula and Sumatra.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Theiflorae (?); Theales (?). Cronquists Subclass Dilleniidae; Theales. APG 3 core angiosperms; core eudicot; Superorder Asteranae (but this conflicts with the embryology as reported by Davis, 1966); Order Ericales.
Species 1–2. Genera 1; only genus, Pentaphylax.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using 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).
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th December 2012. http://delta-intkey.com’.