This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Mimulus Langsdorffii Donn; Sims. Bot. Mag.
pl. 1501. 1812. Mimulus guttatus DC. Cat. Hort. Monsp. 127.
Perennial by stolons, glabrous or puberulent; stem rather stout, simple or branched; branches spreading. Leaves ovate to obo-vate, dentate or denticulate, obtuse at the apex, rounded, narrowed or cordate at the base, 1'-3' long, the lower short-petioled, the upper smaller, sessile or clasping; peduncles shorter than or equalling the flowers; calyx oblique; corolla yellow, 1'-2' long, the lower lip bearded at the base, often blotched with red or purple; fruiting calyx about 1/2' long; seeds longitudinally striate.
In wet meadows, Norfolk, Conn., and southern New York. Introduced from California. Summer.
371. 1846. M. glabratus var. Jamesii A. Gray, Syn. Fl. N. A. Ed.
2, 21: 447. 1886.
Perennial by stolons, glabrous or nearly so; stems slender, creeping, diffusely branched, rooting at the nodes, 6-18' long. Leaves broadly ovate, orbicular or broader, very obtuse, denticulate or entire, membranous, truncate, subcordate, or rarely narrowed at the base, palmately veined, short-petioled or the upper sessile, \'~\' in diameter; peduncles slender, longer than the oblique calyx in fruit, about as long as the leaves; calyx scarcely toothed, 3"-4" long at maturity; corolla yellow, 4"-6" long, the lower lip bearded at the base within, the throat broad; seeds nearly smooth.
In brooks and swamps, Ontario to Illinois, Nebraska, Wyoming and Colorado. June-Sept.
Perennial, villous-pubescent, viscid, musk-scented; stems creeping and ascending, branched, slender, 6'-12' long. Leaves ovate or oblong, short-petioled, acute or obtuse at the apex, denticulate, rounded or subcordate at the base, 1-2' long, 5"-12" wide; peduncles slender, longer than the calyx; flowers 1' long or less; calyx-teeth lanceolate, acuminate, nearly equal; corolla yellow, 2-3 times as long as the calyx.
In wet places, Newfoundland to Pennsylvania, Ontario and Michigan; apparently introduced from western North America, where it is widely distributed. June-Sept.
Mazus japonicus (Thunb.) Kuntze, a low herb with mostly basal, slender-petioled obovate repand leaves and racemose violet flowers, the campanulate calyx not angled, has been found at Washington, D. C, and abundantly about New Orleans, La. It is native of eastern Asia.