Description from Flora of China
Herbs annual or perennial, sparsely strigose or hispid, rarely soft appressed pubescent. Stems erect or spreading. Leaves alternate. Cymes terminal, widely spaced in fruit, scorpioid; bracts lanceolate. Calyx 5-parted nearly to base or less; lobes equal or unequal, linear to triangular, often slightly enlarged in fruit. Corolla blue-purple or yellowish, regular or slightly zygomorphic; tube usually longer than calyx, straight or arcuate or geniculate curved; throat appendages scaly or tuberculate and short pubescent; limb campanulate; lobes 5, equal or unequal, apex obtuse. Stamens inserted at or below middle of corolla tube, included; filaments short, filiform; anthers ovate-oblong, apex obtuse. Ovary 4-divided. Style included in corolla tube; stigma capitate, 2-cleft. Gynobase flat. Nutlets straight, reniform, or oblique-ovoid, reticulate-wrinkled; attachment scar at or near base, margin ringlike, thickened, hardened.
About 50 species: N Africa, C and W Asia, Europe; one species in China.