Orobanche

Holoparasitic, annual herbs attached to roots, lacking chlorophyll, variously coloured, usually +/- covered with gland-tipped papillose hairs; stems solitary or fascicled, simple or branched usually from base, fleshy but slender. Leaves alternate, mostly scale-like, upper ones sometimes bract-like, sometimes crowded near base, distant higher up. Flowers irregular, solitary in axils of upper scales or bracts, bracteolate or not, sessile or lowest ones pedicelled, usually in many-flowered spikes or racemes, at length elongated and lax. Calyx tubular, (2)4-lobed, membranous, shorter than corolla tube; tube campanulate with 4 lobes arising +/- in middle, or divided to base at front and back into 2 subequal, usually 2-lobed parts. Corolla tubular, +/- distinctly bilabiate, 4- or 5-lobed, marcescent; tube somewhat constricted near base or at middle, usually +/- funnel-shaped above, gently curved; upper lip 2-lobed or emarginate, porrect, interior in bud; lower lip 3-lobed; lobes equal or subequal, +/- rounded, separated by prominent folds. Stamens 4, didynamous, arising low down in corolla tube, +/- included; filaments usually thickened or flattened towards base and surrounded by a luniform gland above point of attachment, glabrous or +/- hairy at least below; anthers often cohering below stigma, bithecate; thecae usually equal, all fertile, parallel or slightly divergent, mucronate at base; staminodes 0. Nectary obscure. Ovary unilocular, ovoid-ellipsoid; ovules many on 4 parietal placentas; style thick and somewhat flattened, included, persistent; stigma fleshy, 2-4-lobed, sometimes obscurely so, lobes papillose above. Fruit a bivalved, loculicidal, capsule. Seeds very many, minute, subglobose, testa reticulate, membranous. x = 19 (12) (aneuploids, high polyploidy).