Mimulus glabratus Kunth
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stems weak, prostrate to ascending, glabrous or minutely villosulous above; lvs palmately veined, the lower petioled, the upper sessile or nearly so; fls from the upper axils, on pedicels 1–4 cm; cal accrescent in fr, very irregular, the throat oblique, the upper median lobe broadly ovate and blunt (sometimes mucronate), the other 4 lobes very short or obsolete; cor bright yellow, sometimes with reddish-brown dots, the throat open, the lower lip bearded; 2n=28, 30, 60, 62, 90, 92. In shallow water or very wet places, especially in calcareous situations; Mich. to Man. and Mont., s. to S. Amer. June–Sept. Most of our plants belong to var. fremontii (Benth.) A. L. Grant, with entire or repand to irregularly denticulate, subrotund to ± reniform or occasionally rotund- ovate lvs, the cor mostly 8–15 mm; c. and n. Great Plains, e. to Ill., Mich., and Ont. Var. michiganensis (Pennell) Fassett, local near the Straits of Mackinac, Mich., has more ovate or oval, more obviously toothed lvs and mostly larger fls, the cor 15–25 mm; it may reflect ancient introgression from no. 5.