The Families of Flowering Plants
The Families of Flowering Plants | |
~ Grossulariaceae
Excluding Pterostemonaceae
Habit and leaf form. Trees, or shrubs. Plants non-succulent. Leaves evergreen, or deciduous; alternate; ‘herbaceous’, or leathery (sometimes holly-like); petiolate; non-sheathing; simple. Lamina entire. Leaves stipulate. Lamina margins serrate, or dentate (or spinose).
Leaf anatomy. Minor leaf veins without phloem transfer cells (Itea).
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent.
Reproductive type, pollination. Plants hermaphrodite, or polygamomonoecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in panicles. The ultimate inflorescence unit cymose. Inflorescences terminal, or axillary; densely elongate-racemiform or shortly cymose. Flowers small; fragrant; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present (as a turbinate ‘calyx tube’). Hypogynous disk (or perigynous disk) present; intrastaminal; annular.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous (on the hypanthium); regular; persistent; valvate, or open in bud. Corolla 5; 1 whorled; polypetalous (the petals narrow); valvate; regular; white.
Androecium 5. Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous (?); filantherous (the filaments subulate). Anthers dorsifixed; non-versatile; dehiscing via longitudinal slits; introrse (oblong or ovate). Pollen grains aperturate; 2(–3) aperturate; porate.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; synovarious, or eu-syncarpous (the two connate styles finally becoming free, or remainong united by the capitate stigma); superior to partly inferior. Ovary 2 locular. Gynoecium stylate. Styles 2; free, or partially joined (initially connate, subsequently free or remaining joined only by the stigma); apical. Placentation axile. Ovules 4–50 per locule (‘few to many’); usually biseriate.
Fruit non-fleshy; dehiscent; a capsule (narrow or ovoid). Capsules septicidal. Seeds sparsely endospermic. Endosperm fleshy. Seeds flattened, oblong or scobiform. Embryo well differentiated (large). Micropyle not zigzag.
Physiology, biochemistry. Cyanogenic. Cynogenic constituents tyrosine-derived (triglochinin?). Proanthocyanidins present; delphinidin. Flavonols absent. Ellagic acid absent (Itea).
Geography, cytology. Holarctic, Paleotropical, and Cape. Temperate to tropical. East and Southeast Asia, eastern North America, tropical and South Africa.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae; Cunoniales. Cronquist’s Subclass Rosidae; Rosales. APG 3 core angiosperms; core eudicot; unplaced at Superordinal level; Order Saxifragales.
Species 17. Genera 2; Itea, Choristylis.
Bohm et al. (1988) provide details of Itea flavonoids.
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 specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th November 2009. http://delta-intkey.com’.