The Families of Flowering Plants
The Families of Flowering Plants | |
~ Celastraceae
Habit and leaf form. Small trees, or shrubs. Switch-plants; with the principal photosynthesizing function transferred to stems (and the green, striate branches ending in spines). Leaves much reduced (represented by minute, deltoid scales, above each of which is a conspicuous, black, triangular gland field). Xerophytic. Leaves minute; alternate; membranous.
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Wood parenchyma apotracheal.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The terminal inflorescence unit cymose. Inflorescences lateral; short, 3–7 flowered cymes. Flowers minutely bracteate; regular; 5 merous; cyclic; tetracyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5 (small, minutely glandular-fringed); 1 whorled; gamosepalous (connate basally); regular; persistent; imbricate. Corolla 5; 1 whorled; polypetalous; imbricate; regular; thickish, carinate within; deciduous.
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; alternating with the corolla members; filantherous (the filaments subulate, persistent). Anthers apically introrse.
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 (thick, persistent). Stigmas 1; 5 lobed. Placentation axile. Ovules (3–)6 per locule; horizontal; biseriate; amphitropous.
Fruit non-fleshy (woody); dehiscent; a capsule. Capsules septicidal and loculicidal (partially loculicidal from the top). Seeds endospermic (the endosperm thin, fleshy); ascending, 1–2 per loculus; winged (the wing basal, membranous). Embryo straight.
Geography, cytology. Holarctic. Temperate to sub-tropical. Southwest U.S.A.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Santaliflorae (?); Celastrales (?). Cronquist’s Subclass Rosidae; Celastrales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid I; unassigned at ordinal level (as a synonym of Celastraceae). Species 2. Genera 2; Acanthothamnus, Canotia.
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: 10th April 2008. http://delta-intkey.com’.