Cor salverform to broadly funnelform, equaling to much exceeding the cal, the throat obstructed by the fornices; stamens included; nutlets smooth and shining, with an evident raised margin all the way around, and with a small, basilateral scar, the gynobase low and broad; glabrous or strigose (but not hispid or setose) herbs with blue or less often white (rarely yellow) fls in terminal, naked, helicoid cymes ("racemes"), or the lower fls scattered among the lvs; fruiting pedicels erect or spreading. 50, temp. and boreal.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.