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Common Monkeyflower

Mimulus guttatus

by Kathy Lloyd, Montana Native Plant Society

Photo of Common Monkeyflower. Common Monkeyflower

Captain Meriwether Lewis collected a specimen of common monkeyflower, also called yellow monkeyflower, on July 4, 1806. Lewis and nine men had separated from William Clark and the rest of the explorers the day before on July 3 rd . With some misgivings, the captains had split the party into two groups and Lewis headed east to explore the Marias River area while Clark turned south to eventually make his way down the Yellowstone River. Lewis's group was accompanied for a short distance by five Indians who showed them the way to present-day Lewis & Clark Pass. Lewis said in his journal on July 3, 1806, "These people now informed me that the road which they shewed me at no great distance from our Camp would lead us up the East branch of Clark's river and a river they called Cokahlarishkit or the river of the road to buffaloe and thence to medicine river and the falls of the Missouri where we wished to go." This route would lead the travelers up the Clark Fork and Blackfoot Rivers, north along Alice Creek and over Lewis & Clark Pass to the present-day Sun River, called the Medicine River by Lewis. This is just one instance of the invaluable assistance given to the expedition by the original inhabitants of the country.

The specimen Lewis collected along the Blackfoot River, above its confluence with the Clark Fork River, in Missoula County, is housed today in the Lewis & Clark Herbarium at the Academy of Natural Sciences in Philadelphia. Lewis does not mention monkeyflower in his journal and it is one of two specimens collected on July 4 th that still exist. The other is Lewis's mockorange or Philadelphus lewisii. The common monkeyflower specimen bears a label attached by the botanist Frederick Pursh that reads, " On the Waters of Clarks River. Jul. 4th 1806." Pursh was a botanist who was engaged to look at plant specimens from the expedition and prepare drawings of some of the plant species. Lewis's collection of common monkeyflower traveled over Lewis & Clark Pass, down the Missouri River and eventually made its way to St. Louis and then to Philadelphia where Pursh examined it. The specimen was part of a group of plants that were presumed lost until they were fortunately rediscovered in 1896 at the American Philosophical Society and subsequently put on permanent loan to the Academy of Natural Sciences.

Common monkeyflower, or Mimulus guttatus, is a member of the figwort family (Scrophulariaceae), as are garden snapdragons. The resemblance is clear. The plant is variable and can be either an annual with fibrous roots or a perennial with stout stolons. These aboveground stems creep along the soil surface and spread the plant, as do strawberry runners. Common monkeyflower can be as high as three feet or a short dwarf with small leaves. The leaves are opposite on the stem and the lower leaves are attached with a stalk (petiole) to the stem while the upper leaves are stalkless (sessile). The leaves are usually coarsely toothed on the margins. The yellow flowers have red or maroon spots on the wide, hairy throat of the lower lip petal; in fact guttatus means spotted or speckled. The flowers are arranged in a terminal raceme or arise singly from the upper leaf axils.

Common monkeyflower is found in wet places from sea level to mid-elevations in the mountains across northern North America and south from Alaska to northern Mexico. In Montana it is a common sight along creeks, seeps, beaver dams and wet places in the mountains. It has been introduced in Europe, as well. Pursh, in his 1814 Flora Americae Septentrionalis, says of common monkeyflower, "It has lately been introduced into the gardens, and will be a fine addition to our hardy perennial plants." It is hoped that common monkeyflower remains benign in Europe and doesn't become an undesirable pest, as did some of the garden plants introduced from Europe to North America.

Native Indian tribes in North America had several uses for common monkeyflower. A decoction of the stems and leaves was used as a steam bath for soreness in the chest or back. Sacagawea's Shoshone tribe used a poultice of crushed leaves for rope burns or wounds. Other tribes used the plant in tea form for stomachache. Indians and early white settlers also ate the leaves raw or cooked and it is said to have a slightly bitter taste. Muskrats don't seem to mind the taste though, and use the plant throughout the summer.

The name Mimulus comes from a Latin word and refers to "mime," a reference to the funny clown-face made by the fat flower shape. Monkeyflower is another reference to the supposed funny shape of the flower. Funny or not, common monkeyflower is a beautiful native plant with unique historical significance. Its preferred wet habitat is often fragile and should be protected so we can continue to enjoy common monkeyflower and all the other forms of life found in wet places in Montana.