The Families of Flowering Plants
The Families of Flowering Plants | |
~ Zygophyllaceae
Including Agialidaceae Van Tieghem
Habit and leaf form. Small trees, or shrubs (with axillary, simple or forked spines and bitter bark); non-laticiferous and without coloured juice. Leaves alternate; leathery; petiolate; non-sheathing; not gland-dotted; compound; bifoliolate; exstipulate. Lamina margins entire.
Leaf anatomy. Stomata present; anomocytic.
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with fibre tracheids. Vessel end-walls simple. Primary medullary rays wide. Wood partially storied (VP); parenchyma apotracheal.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’. Inflorescences axillary. Flowers fragrant; regular; 5 merous; cyclic. Free hypanthium absent. Hypogynous disk present; intrastaminal; annular (cupular or cushion shaped, 10-grooved).
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; regular; not persistent; slightly imbricate. Corolla 5; 1 whorled; polypetalous (the petals spreading); imbricate; regular; green (-ish). Petals sessile.
Androecium 10. Androecial members free of the perianth; free of one another. Androecium exclusively of fertile stamens. Stamens 10; diplostemonous; both alternating with and opposite the corolla members; filantherous (the filaments filiform). Anthers dorsifixed; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or decussate. Anther wall initially with more than one middle layer; of the ‘monocot’ type. Tapetum glandular. Pollen grains aperturate; 3 and 6 aperturate; colporate and rugate (tricolporate and 6-rugorate); 2-celled.
Gynoecium 5 carpelled. Carpels isomerous with the perianth. The pistil 5 celled. Gynoecium syncarpous; eu-syncarpous; superior to partly inferior (semi-immersed in the disk). Ovary 5 locular; sessile. Gynoecium stylate. Styles 1; attenuate from the ovary; apical; shorter than the ovary (very short, subulate). Stigmas 1; minute. Placentation axile to apical. Ovules 1 per locule; funicled; pendulous; hemianatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization, or fusing only after one has been fertilized (?). Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Endosperm formation nuclear.
Fruit fleshy; indehiscent; a drupe (fleshy, oily, the endocarp bony and 5-angled). The drupes with one stone. Fruit 1 seeded (and unilocular). Seeds non-endospermic. Embryo well differentiated. Cotyledons 2 (thick, corrugated or bilobed). Embryo chlorophyllous. Micropyle zigzag.
Geography, cytology. Paleotropical. Tropical. Tropical Africa to Burma.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae; Geraniales. Cronquist’s Subclass Rosidae; Sapindales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Fabales (as a synonym of Zygophyllaceae).
Species 25. Genera 1; only genus, Balanites.
Illustrations. • Technical details: Balanites (Thonner).
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’.
