Lycopus asper Greene
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Rhizomes tuberous-thickened at the tip, the tuber producing a single stem the next year; stem spreading-hairy, at least on the angles; lvs numerous, narrowly oblong to oblanceolate, 4–10 × 0.6–3.5 cm, sessile or subsessile and usually broad-based, rather coarsely but fairly evenly serrate, glabrous or often scabrous to hirsute-puberulent; cal-lobes 5, narrow, firm, slenderly subulate- pointed, with evident midnerve, distinctly surpassing the mature nutlets; cor 4-lobed, barely surpassing the cal; nutlets mostly 1.6–2.1 × 1.4–1.8 mm, the outer apical margin truncate and often irregularly toothed, the inner angle much shorter and not tuberculate, the set of 4 nutlets therefore with a depressed center; 2n=22. Minn., Io., and Sask. to B.C. and Calif., and intr. about the w. end of Lake Erie in Mich. and Ont.