Densely matted from a branching caudex, the flowering stems 2-10 cm; lower lvs closely imbricate, opposite, obovate to spatulate, 3-6 mm, ciliate; cauline lvs similar, few; fl solitary, erect, usually purple, 1 cm wide; 2n=26, 52. Circumboreal, s. in rocky places to e. Que., n. Vt., n. N.Y., and Wyo. June, July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.