Description from Flora of China
Herbs annual, biennial, or perennial, usually tomentose, villous, or glandular pubescent, rarely glabrous. Leaves spirally or imbricately arranged, ovate, ovate-lanceolate, or lanceolate. Flowers many, in spicate or racemose inflorescences, rarely solitary; bract 1, usually similar to leaves; bractlets 2 or absent. Pedicel short or absent. Calyx cupular or campanulate, apex 4-lobed or nearly 4- or 5-parted, occasionally 5- or 6-toothed, sometimes 2-parted to base and lobes entire or 2-toothed. Corolla bilabiate, curved; upper lip entire, emarginate, or 2-lobed; lower lip 3-lobed, shorter to longer than upper lip. Stamens 4, didynamous, included; filaments base pubescent or glandular pubescent. Ovary 1-locular; parietal placentas 4; ovules numerous. Style elongated, usually persistent; stigma inflated, peltate, or 2-4-lobed. Capsule ovoid-globose or ellipsoid, dehiscing by 2 valves. Seeds numerous, minute, ellipsoid or subglobose; testa reticulate.
About 100 species: mostly in North Temperate regions, less represented in S Central America and E and N Africa; 25 species in China.
Species 1-7 belong to subgen. Phelipanche (Pomel) Tzvelev (bractlets 2), whereas species 8-25 belong to subgen. Orobanche (bractlets absent).