Short-lived perennial to 5 dm; lvs oblong to lanceolate or spatulate, the larger 3-7 cm; racemes naked, seldom over 1 dm; fruiting pedicels 5-15 mm apart, ascending or spreading, to 9 mm; mature cal 4-5 mm, densely pubescent with hooked hairs, the lobes much longer than the tube; cor blue (white), salverform, the limb 5-8 mm wide; nutlets 1.5-2 mm; 2n=14-48. Native of Eurasia, occasionally escaped from cult. in our range. Apr.-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.