The Families of Flowering Plants
The Families of Flowering Plants | |
~ Escalloniaceae, Grossulariaceae
Including Ixerbaceae, Rousseaceae DC.
Habit and leaf form. Small trees, or shrubs; resinous (at least sometimes), or not resinous. Leaves evergreen; alternate, or opposite, or whorled; leathery; petiolate; not gland-dotted; simple. Lamina entire; pinnately veined; cross-venulate. Leaves stipulate (Brexia), or exstipulate. Stipules when present, intrapetiolar; minute, caducous. Lamina margins entire, or serrate, or dentate.
Leaf anatomy. Lamina dorsiventral. Minor leaf veins without phloem transfer cells (Brexia).
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Vessel end-walls scalariform and simple, or simple. Wood parenchyma apotracheal.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in cymes. The terminal inflorescence unit cymose. Inflorescences terminal and axillary (few flowered); few-flowered axillary cymes. Flowers medium-sized to large; regular; 4–6 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present; intrastaminal (conspicuous); of separate members (e.g. as palmate scales opposite the petals), or annular.
Perianth with distinct calyx and corolla; 8–12; 2 whorled; isomerous. Calyx 4–6; 1 whorled; polysepalous; regular; persistent, or not persistent; imbricate, or valvate. Corolla 4–6; 1 whorled; polypetalous, or gamopetalous; imbricate, or contorted (when polypetalous), or valvate (when sympetalous); persistent, or deciduous. Petals when free, clawed.
Androecium 4–6, or 8–12 (if interstaminal scales are regarded as staminodal). Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens, or including staminodes (allowing for the interstaminal scales). Staminodes (if so interpreted) 4–6; more or less petaloid. Stamens 4–6; isomerous with the perianth; oppositisepalous; alternating with the corolla members; filantherous (with large anthers). Anthers dorsifixed; non-versatile; dehiscing via longitudinal slits; introrse. Pollen with viscin strands (the grains cohering). Pollen grains aperturate; 3–5 aperturate; colporate.
Gynoecium 4–7 carpelled. Carpels isomerous with the perianth to increased in number relative to the perianth. The pistil 4–7 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 4–6(–7) locular. Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1; truncate, or capitate; dry type; non-papillate; Group II type. Placentation axile. Ovules 2–50 per locule (to ‘many’); funicled; horizontal; apotropous; collateral, or biseriate; anatropous; bitegmic. Endothelium differentiated. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids elongated. Endosperm formation nuclear.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent; a capsule, or a berry, or a drupe. Capsules when capsular, loculicidal (Ixerba). The drupes with one stone (one-celled). Seeds almost non-endospermic (? see Lindley 1853). Embryo straight.
Physiology, biochemistry. Not cyanogenic.
Geography, cytology. Paleotropical and Antarctic. Sub-tropical to tropical. East Africa, Madagascar, Mascarene Is., New Zealand.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae; Saxifragales. Cronquist’s Subclass Rosidae; Rosales. APG (1998) Eudicot; core Eudicot; Rosid; unassigned to Eurosid I or Eurosid II, or Eurosid I; (if ‘unclassified Rosid’) unassigned to order; (if Eurosid I) unassigned at ordinal level (as a synonym of Celastraceae). Species 11. Genera 3; Brexia, Ixerba, Roussea.
APG (1998) list ‘Ixerbaceae’ as unclassified Rosid, then list Brexiaceae as a synonym ofCelastraceae.
Illustrations. • Technical details (Brexia, Ixerba). • Technical details, from Lindley (Brexia).
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: 9th September 2008. http://delta-intkey.com’.
