Fibrous-rooted perennial from slender stolons or superficial rhizomes, the stems lax, 1-4 dm, retrorsely scabrous (or hirsute) to subglabrous, pilose at the nodes; lvs all about alike, petiolate, the blade glabrous or hirsute, rotund-cordate to cordate-reniform, strongly crenate, 1-3 cm; fls short-pedicellate; cal narrow, 5-6 mm, hirtellous-scabrous, the upper teeth the longer; cor blue-violet, purple-maculate, 13-23 mm, or in pistillate plants only 8-15 mm, the anthers then minute and included in the cor-tube; 2n=18, 36. Moist woods and various disturbed habitats; native of Eurasia, now found throughout our range. Apr.-June. (Nepeta h.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.