Much like no. 1 [Mimulus ringens L.], and hybridizing with it, but the lvs tapering to a narrowly winged petiole 1-2 cm, the blade lanceolate to ovate, more sharply and coarsely toothed; pedicels at anthesis mostly 2-10 mm, to 15 mm in fr; 2n=22. Wet woods and shady streambanks; Conn. to s. Ont., s. Mich., Io., and Kans., s. to Fla. and Tex. July, Aug. Hybridizes with no. 1 [Mimulus ringens L.].
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.