A Singular Plant

Elkhorn, Clarkia pulchella

Flower with four purple petals

Courtesy Lewis and Clark Trail Heritage Foundation

On their return journey in 1806, the Corps of Discovery had to camp for nearly a month (May 14 to June 10) in the vicinity of present-day Kamiah (pronounced KAM-ee-eye), Idaho, to wait for the snow to melt in the Bitterroot Mountains. Lewis used this time to study and describe many of the plant specimens he had collected. The flower pictured here is one of those, and his description of it is among his most detailed, running to nearly 500 words.

In some localities the plant's most common name today is ragged robin, but it is also known as pink fairy and deerhorn. In the spring of 1807 Lewis turned over his plant specimens to the young German-American botanist, Frederick Pursh, who gave this flower the scientific name Clarkia pulchella, in honor of William Clark; pulchella means beautiful. Appropriately, the best of its common names today is clarkia.

Seven different species of this lovely flower are found between British Columbia and southern Oregon, and eastward to South Dakota. Only two of them grow in the Rocky Mountains.

It is not known exactly how many specimens of plants Lewis and Clark collected. Those that were acquired between Fort Mandan and the Falls of the Missouri were cached underground at White Bear Islands—the upper portage camp—and were destroyed by springtime floodwaters before Lewis returned on July 13, 1806. All but one of the specimens Lewis gathered on the upper Missouri, Jefferson, and Beaverhead rivers, as well as in the vicinity of Lemhi Pass, which were cached at Camp Fortunate, were similarly destroyed. The only one of the latter that survived was the golden currant (Ribes aureum).

At the present time there are 232 Lewis and Clark herbarium specimens in two different locations. The majority are at the Academy of Natural Sciences in Philadelphia. Eleven are at Kew Gardens in London, England. One is at the Charleston Museum in Charleston, South Carolina.

Further reading

Raymond Burroughs, The Natural History of the Lewis and Clark Expedition. East Lansing: Michigan State University Press, 1995.

Paul Russell Cutright, Lewis and Clark: Pioneering Naturalists. Lincoln: University of Nebraska Press, 1969.

Richard M. McCourt, Catharine Hawks and Earle E. Spamer, "The Lewis and Clark Herbarium of the Academy of Natural Sciences; Part 2, Saving an American Treasure: Preservation of the Herbarium on the Bicentennial of the Expedition," Notulae Naturae, No. 476 (December 2002).

Gary E. Moulton, ed., The Journals of the Lewis & Clark Expedition (13 vols, Lincoln: University of Nebraska Press, 1983–2001), Vol. 12, Herbarium of the Lewis & Clark Expedition.

James L. Reveal, Gary E. Moulton, and Alfred E. Schuyler, "The Lewis and Clark Collections of Vascular Plants: Names, Types, and Comments," Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 149 (29 January 1999), 1–64.

A. Scott Earle and James L. Reveal, Lewis and Clark's Green World: The Expedition and its Plants (Helena, Montana: Farcountry Press, 2003), 167.