Bartsia

Annual, viscid-pubescent herbs, parasitic on grass roots; stems simple or slightly branched in inflorescence, erect, leafy. Leaves opposite, sessile or lowest shortly petiolate, narrow-lanceolate, obtuse, coarsely toothed or shallowly pinnatifid, spreading. Flowers sessile, in axils of leaves or bracts, in dense terminal spikes, usually unbranched, elongated in fruit. Bracts almost as long as flowers. Calyx ovoid, somewhat inflated, tetragonous, shortly 4-lobed, densely tomentose; tube campanulate; lobes deltoid, obtuse or rounded. Corolla tubular, bilabiate, almost personate, 4-lobed; tube subcylindrical, +/- as long as calyx tube, slightly curved; upper lip erect, narrow, hooded, concave, entire, rather shorter than lower one, inside in bud; lower lip dilated, spreading, 3-lobed, middle lobe the smallest; palate bigibbous, prominent. Stamens 4, all fertile, didynamous, slightly exserted; upper pair arising at base of upper corolla lip, lower pair in lower part of corolla tube; all lying in hollow of upper lip; filaments filiform; anthers free, pendulous, bithecate; thecae oblong, shortly mucronulate at base, equal, parallel, +/- bearded or at length glabrous. Ovary bilocular, ovoid, hirsute; ovules many, on thick, bifid placentas; style linear, exceeding stamens, +/- exserted, curved downwards near apex, hairy; stigma short, somewhat thickened, clavate, bifid. Fruit a somewhat flattened, ovoid capsule, coriaceous, pubescent, turgid, loculicidal, bisulcate and enclosed in calyx. Seeds many, small, convex on one side, flattish on other, longitudinally ribbed; testa membranous. x = 6 (7) (aneuploids, high polyploidy).