Dipsacaceae Juss. → Browse taxa…

Dipsacaceae Juss.
Gen.Pl. 194 (1789)

Name Status: Not Current

Scientific Description
Leslie Watson, Friday 3 October 2008

Common name. Teasel Family.

Habit and leaf form. Herbs. Annual, or biennial, or perennial; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Young stems cylindrical, or tetragonal. Sometimes tuberous. Heterophyllous, or not heterophyllous. Leaves opposite (usually), or whorled (rarely); ‘herbaceous’, or leathery; petiolate, or subsessile, or sessile; connate, or not connate; simple, or compound; when compound, pinnate. Leaf blades when simple dissected, or entire; when dissected, pinnatifid; pinnately veined; cross-venulate. Leaves without stipules. Stem anatomy. Nodes tri-lacunar, or multilacunar. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in heads (these dense, the receptacle usually hairy or scaly). The terminal inflorescence unit cymose. Inflorescences scapiflorous; dense, involucrate heads; with involucral bracts; pseudanthial. Flowers bracteolate (the two bracteoles supposedly joined to form the involucel); small; very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers cyclic; tetracyclic. Free hypanthium absent. Perianth with distinct calyx and corolla (the calyx small, variously constituted); 8, or 10; 2 -whorled; isomerous. Calyx 4 (by fusion of two members, cf. Veronica), or 5 (but often represented by five or up to ten pappus-like bristles); represented by bristles (often), or not represented by bristles; 1 -whorled; polysepalous (of teeth or bristles), or partially gamosepalous (cupular, entire or variously divided); entire, or lobed; when not entire, lobulate, or blunt-lobed, or toothed; regular; usually persistent. Epicalyx present (usually, supposedly formed from two fused bracteoles), or absent. Corolla 4 (by fusion of two members), or 5; 1 -whorled; gamopetalous; imbricate; funnel-shaped, or tubular; unequal but not bilabiate, or bilabiate; white, or purple, or blue. Androecium 4, or 2–3 (rarely). Androecial members adnate (near the top of the tube); all equal, or markedly unequal; free of one another, or coherent; when united, 2 - adelphous; 1 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes if present, 1–2. Stamens 4, or 2–3; didynamous (sometimes), or not didynamous, not tetradynamous; reduced in number relative to the adjacent perianth, or isomerous with the perianth; oppositisepalous; all alternating with the corolla members. Anthers dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 2 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous (but pseudomonomerous); synstylovarious to eu-syncarpous; inferior. Ovary unilocular; 1 locular. Gynoecium median. Epigynous disk present. Gynoecium non-stylate. Styles 2; apical. Stigmas 1–2; simple, or unequally 2 - lobed; dry type; non-papillate; Group II type. Placentation apical. Ovules in the single cavity 1; pendulous; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; achene-like. Dispersal unit the remains of the flower (with the ‘achene’ enclosed in the epicalyx and the persistent calyx limb). Fruit 1 seeded. Seeds endospermic. Endosperm oily. Embryo well differentiated. Cotyledons 2. Embryo chlorophyllous (4/16); straight. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Holarctic. World distribution: Old World, chiefly North temperate Eurasia and tropical and southern Africa. X = 5–10. 150 species.

Economic uses, etc. Some ornamentals (Scabiosa, Cephalaria); teasels (Dipsacus) are sometimes noxious weeds, and the heads are used for fulling cloth.

Keys to Dipsacaceae Juss.