The families of flowering plants.
Habit and leaf form. Trees and shrubs; resinous. Leaves alternate; petiolate; compound; ternate, or pinnate (usually), or unifoliolate (rarely ‘simple’). Lamina pinnately veined; cross-venulate. Leaves exstipulate.
Leaf anatomy. Lamina with secretory cavities (in th phloem of the petiole). Secretory cavities containing resin. Minor leaf veins without phloem transfer cells.
Stem anatomy. Secretory cavities present (in the primary phloem); with resin. 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. Vessel end-walls simple. Wood parenchyma paratracheal.
Reproductive type, pollination. Plants dioecious. Female flowers without staminodes. Gynoecium of male flowers vestigial, or absent.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. The ultimate inflorescence unit cymose. Inflorescences many-flowered panicles. Flowers bracteate; (bi-) bracteolate; small; regular; cyclic. Hypogynous disk present (in male flowers), or absent (minute or lacking in female flowers).
Perianthsepaline, or absent (if the ‘calyx’ is considered to be bracteal); 1–5. Calyx 1–2 (or missing, in male flowers), or 2–5 (in female flowers); polysepalous (small, scarious).
Androecium in male flowers, 3–5. Androecial members adnate; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 2–5; isomerous with the perianth to diplostemonous; filantherous (the filaments very short, adnate to the disk). Anthers basifixed (large, ovoid); dehiscing via longitudinal slits; latrorse; tetrasporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with more than one middle layer (3); of the ‘basic’ type. Tapetum glandular. Pollen grains aperturate; about 3–8 aperturate (not sharply delimited); colpate (colpoidate), or foraminate, or rugate; 2-celled.
Gynoecium3 carpelled. Carpels reduced in number relative to the perianth, or isomerous with the perianth. The pistil 1 celled. Gynoecium syncarpous; synstylovarious; superior. Ovary 1 locular. Gynoecium stylate. Styles 1; apical; short. Stigmas 3 (spreading). Placentation basal. Ovules in the single cavity 1; funicled; pendulous; non-arillate; anatropous; unitegmic (by fusion?); crassinucellate. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Endosperm formation nuclear.
Fruit fleshy to non-fleshy; indehiscent; a drupe (oblique, more or less compressed, with thin exocarp and bony endocarp). The drupes with one stone. Fruit 1 seeded. Seeds non-endospermic. Embryo well differentiated. Cotyledons 2. Embryo chlorophyllous (1/4).
Physiology, biochemistry. Not cyanogenic. C3. C3 physiology recorded directly in Pistacia.
Geography, cytology. Holarctic, Paleotropical, and Neotropical. Temperate to tropical. Mediterranean to Afganistan, Eastern Asia, Malaysia, Southeast U.S.A. and Central America.
Taxonomy.Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae; Sapindales. Cronquist’s Subclass Rosidae; Sapindales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Sapindales (as a synonym of Anacardiaceae).
Species 10. Genera 1; only genus, Pistacia.