Lvs softly and densely pubescent or sometimes subtomentose beneath, with long stiff hairs on the veins; axis of the infl glandular or not, ±hirsute with long spreading hairs; hypanthium hirsute throughout with long, spreading or ascending hairs; pet 4-5 mm; 2n=28. Formerly used in folk-medicine and as a source of a golden yellow dye. Native of Eurasia, occasionally intr. in our range.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.