The families of flowering plants.
~Scrophulariaceae sensu lato
Habit and leaf form. Trees, or shrubs, or lianas; non-laticiferous and without coloured juice. Self supporting, or climbing. Leaves opposite, or alternate to opposite (alternate only in Buddleja alternifolia), or whorled; when whorled, 3 per whorl; petiolate to sessile; connate (in some Buddleja species), or not connate; simple. Lamina pinnately veined; cross-venulate. Leavesstipulate, or exstipulate (the stipules often reduced, but then represented by a ‘stipular line’ linking the opposing leaf bases). Stipules interpetiolar; without colleters. Lamina margins entire, or serrate, or dentate.
Leaf anatomy. Hairs present; eglandular and glandular (glandular hairs usually present, contrasting with other Loganiaceae sensu lato); multicellular. Complex hairs usually present; peltate, or stellate, or capitate.
Minor leaf veins without phloem transfer cells (Buddlejaceae).
Stem anatomy. Young stems cylindrical, or tetragonal. Primary vascular tissue centrifugal. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with tracheids (e.g., commonly inBuddleja), or without tracheids; with fibre tracheids (occasionally), or without fibre tracheids; with libriform fibres, or without libriform fibres (septate fibres recorded in some Buddleja species, Peltanthera, Nuxia). Vessel end-walls oblique; simple. Vessels without vestured pits. Primary medullary rays mixed wide and narrow (mostly), or narrow (uniseriate and multiseriate). Tile cells present, or absent. Wood ring porous to diffuse porous (climate-related); parenchyma paratracheal (or absent).
Reproductive type, pollination. Plants hermaphrodite (mostly), or dioecious (e.g., most American Buddleja species). Female flowers with staminodes. Gynoecium of male flowers pistillodial. Plants homostylous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes, or in racemes, or in heads, or in panicles. The ultimate inflorescence unit cymose (usually), or racemose (Gomphostigma). Inflorescences terminal, or axillary, or terminal and axillary; variable, mostly cymose and paniculate or capitate. Flowers bracteate (lower bracts sometimes leafy, otherwise bracts scale- or sepal-like); bracteolate; regular, or somewhat irregular. The floral irregularity (when irregular) involving the perianth (the sepals often unequal). Flowers 4 merous (mostly), or 5 merous (Peltanthera only); cyclic; tetracyclic. Hypogynous disk absent (usually), or present (Gomphostigma); intrastaminal; annular.
Perianthwith distinct calyx and corolla; 8, or 10; 2 whorled; isomerous. Calyx 4; 1 whorled; gamosepalous; five, rarely four blunt-lobed, or toothed; unequal but not bilabiate, or regular; persistent; non-accrescent; imbricate.Corolla 4; 1 whorled; gamopetalous; imbricate, or valvate (with both conditions represented in Buddleja); variously shaped, hairy or glabrous within; regular; white, or yellow, or white to yellow, or orange, or purple, or blue (or violet).
Androecium 5 (Peltanthera), or 4. Androecial members adnate (epipetalous);all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 4; inserted midway down the corolla tube, or in the throat of the corolla tube; isomerous with the perianth; oppositisepalous; alternating with the corolla members; filantherous, or with sessile anthers. Anthers dorsifixed (or peltate); dehiscing via longitudinal slits; introrse; bilocular (mostly, although the locules are sometimes apically confluent), or four locular (Androya); tetrasporangiate. Tapetum glandular. Pollen grains aperturate; 3–4(–5) aperturate; colporate; 2-celled.
Gynoecium 2 carpelled, or 4 carpelled (ostensibly, in a few Buddleja species). The pistil 2 celled (usually), or 4 celled (in the berries of some Buddleja species). Gynoecium syncarpous; synstylovarious, or eu-syncarpous; superior. Ovary 2 locular, or 4 locular. Locules secondarily divided by ‘false septa’ (accounting for occasional 4–celled gynoecia in species of Buddleja?), or without ‘false septa’. Gynoeciummedian; stylate. Styles 1 (persistent); attenuate from the ovary; apical. Stigmas 1 (unbranched); wet type; papillate; Group III type. Placentation axile. Ovules 20–50 per locule (or more); pendulous, or ascending; hemianatropous; unitegmic; tenuinucellate. Endothelium differentiated (observed in several species of Buddleja), or not differentiated (?). Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; persistent. Synergids pear-shaped. Hypostase present. Endosperm formation cellular. Endosperm haustoria present; chalazal and micropylar. Embryogeny onagrad.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent; a capsule (usually), or a berry, or a drupe. Capsules loculicidal. Fruit 4–50 seeded (‘several to many’). Seeds endospermic (the endosperm fleshy or starchy); winged, or wingless. Cotyledons 2. Embryo achlorophyllous (1/3); straight.
Physiology, biochemistry. Not cyanogenic. Alkaloids present (e.g. Androya decaryi, Nicodemia, some Buddleja species), or absent. Iridoids detected; ‘Route II’ type (decarb.). Verbascosides detected (3 genera). Cornoside not detected. Proanthocyanidins absent. Flavonols present, or absent; kaempferol (trace). Ellagic acid absent (2 genera). Saponins/sapogenins present, or absent. Sugars transported as sugar alcohols + oligosaccharides + sucrose (in 5 Buddleia species).
Geography, cytology. Temperate to tropical. Widespread, tropical and warm temperate. X=7 (Gomphostigma)/19(Buddleja,Emorya, Nuxia). Supposed basic chromosome number of family: 7 and 19. Ploidy levels recorded: 2, 4, 6, 12, 16, and 38.
Taxonomy.Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Lamiiflorae; Scrophulariales. Cronquist’s Subclass Asteridae; Scrophulariales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Lamiales (as a synonym of Scrophulariaceae).
Species 150. Genera 9; Androya, Buddleja, Emorya, Gomphostigma,Nicodemia, Nuxia, Peltanthera.
General remarks. See Leeuwenberg 1980, under Loganiaceae. Removal of Buddleja and related genera from Loganiaceae has long seemed justified. Their nearest neighbour in terms of the present descriptions is Scrophulariaceae, although significant ‘esoteric’ characters may have been inadequately screened. See comments under Loganiaceae re recent cladistic and molecular studies of Loganiaceae sensu lato. For discussion of broader classificatory problems posed by Scrophulariaceae, impinging on Bignoniaceae, Buddlejaceae,Callitrichaceae, Plantaginaceae, Hippuridaceae, Lentibulariaceae, and Hydrostachydaceae, and such problem genera as Paulownia and Schlegelia, see Olmstead and Reeves (1995), who provide preliminary insights from chloroplast gene sequencing.