Cal deeply cleft, commonly with small reflexed auricles in the sinuses; cor campanulate to rotate, white to blue or purple; stamens and style included; ovules 2-several on each of the 2 large, parietal placentas; fr unilocular, 2-valved; seeds with an obscure to evident, partial or complete covering (cucullus) external to the seed-coat; delicate, taprooted annuals with opposite or less often alternate, mostly pinnatifid or pinnatilobate lvs, the fls solitary in the axils or some in a loose, few-fld terminal cyme. 11, N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
