The families of flowering plants.
Habit and leaf form. Small,Olea-like trees; non-laticiferous and without coloured juice. Leaves opposite; simple. Lamina entire; lanceolate; pinnately veined. Leavesexstipulate. Lamina margins entire.
Leaf anatomy. Stomata mainly laterocytic.
Stem anatomy. Nodes unilacunar (with one trace). Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem without tracheids; with libriform fibres; with vessels. Vessel end-walls horizontal; simple. Vessels without vestured pits. Primary medullary rays mixed wide and narrow.
Reproductive type, pollination. Fertile flowersfunctionally male, or functionally female. Plants dioecious. Pollination anemophilous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The ultimate inflorescence unit cymose. Inflorescences axillary. Flowers ebracteate; ebracteolate; small; regular. Free hypanthium absent.
Perianthsepaline; 3, or 4; 1 whorled. Calyx 3, or 4 (the sepals of the female flowers pinnately net-veined); 1 whorled; gamosepalous (at the base). Calyx lobes markedly longer than the tube. Calyx regular; persistent; in the female flowers, slightly accrescent; of male flowers, valvate.
Androecium 6–9(–12). Androecial members free of the perianth; free of one another. Androecium exclusively of fertile stamens. Stamens 6–9(–12); diplostemonous to triplostemonous; erect in bud; filantherous (with very short filaments). Anthers basifixed; dehiscing via longitudinal slits; elongate, the connective apiculate. Pollen grains aperturate; 3 aperturate; colporate (colporoidate).
Gynoecium 1–3 carpelled. Carpels reduced in number relative to the perianth to isomerous with the perianth. The pistil 1 celled (when monomerous, i.e. usually), or 2–3 celled (when semicarpous). Gynoecium monomerous (usually), or apocarpous, or syncarpous; of one carpel (usually), or eu-apocarpous, or semicarpous (the carpels sometimes joined basally); superior. Carpel long stylate; apically stigmatic (the stigma decurrent on the long style); 1 ovuled. Placentation apical. Ovary 2 locular, or 3 locular. Styles free; apical. Placentation when semicarpous, apical. Ovules 1 per locule; pendulous; anatropous; apparently unitegmic.
Fruit non-fleshy; an aggregate (when G 2 or 3), or not an aggregate (when monomerous). The fruiting carpel when apocarpous or monomeric, indehiscent; nucular (shortly beaked). Fruit when semicarpous, of 2–3 basally joined nucules(?). Seeds non-endospermic. Embryo well differentiated. Cotyledons 2. Embryo straight.
Physiology, biochemistry. Ellagic acid present.
Geography, cytology. Paleotropical. Sub-tropical. North East Africa, Arabia.
Taxonomy.Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Malviflorae; Urticales. Cronquist’s Subclass Hamamelidae; Urticales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Rosales.
Species 1. Genera 1; Barbeya oleoides the only representative.