Cor salverform or broadly funnelform, the tube about as long as the cal, the throat closed by the fornices; stamens and style included; fruiting pedicels erect or spreading; nutlets erect and connivent, narrowly attached to the elongate gynobase along the median ventral keel (the lower part rounded and free), bearing one or more rows of glochidiate prickles along the continuous dorsomarginal ridge or cupulate border; rough-hairy annuals with erect stems, each branch ending in an elongate, bracteate false raceme (helicoid cyme) of small, blue or occasionally white fls. Ca. 12, mainly N. Hemisphere.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.