NPS collection

Grasses
Whitman Mission is located on the southern extreme of the Palouse Prairie Region in eastern Washington state. Originally, this prairie was dominated by perennial grasses, principally bluebunch wheatgrass, which flourished over the plains. Intermixed with it were smaller patches of sandberg bluegrass and Idaho fescue. Large native herbivores were generally absent from the Palouse, and because of this, the grasses evolved with a low resistance to grazing. Subsequent grazing by domestic livestock and extensive cultivation for wheat are the main reasons why native perennial grasslands are now rare on the Palouse. more . . .

NPS collection

Trees & Shrubs
Whitman Mission National Historic Site is located in what was once an extensive grassland. Except for in the mountains, trees would have been relatively few and found mostly next to streams and rivers. When the Whitmans came they wanted trees. Dr. Whitman wrote to friends back east asking for locust, chestnut, and walnut seeds. Narcissa obtained sprouts of apple and peach trees from Fort Vancouver. Today the park grounds include trees and shrubs planted by landscapers, which add beauty and provide shade. An apple orchard was created to represent the one planted by Dr. Whitman. List of trees found at Whitman Mission.

NPS collection

Forbs
Most plants encountered in daily life are some type of flowering plant, for example grasses, daisies, roses, and oak trees. Non-woody flowering plants that aren't a type of grass are known as "forbs." The Whitman Mission grounds are dominated by grasses, trees and shrubs, but if one looks carefully a variety of forbs can be seen.

NPS collection

Historic Landscape
It is probable that at the time the mission was established, a mixture of three plant communities occupied the site: a narrow plant community consisting of dense tangled thickets of willows, cottonwoods, wild dogwoods, blackberries, elderberries, and other species common to riparian areas probably occurred in the floodplains along the Walla Walla River and nearby Mill Creek; an association of perennial grasses, shrubs, and native forbs occurred on the hillsides where soil depths and drainage were greater; perennial grasses common to the Palouse dominated the rest of the mission site.

NPS collection

Exotics
In 1997, an inventory of exotic pest plant species identified the following six species of concern: field bindweed (Convolvulus arvensis), jointed goatgrass (Aegilops cylindrica), poison hemlock, (Conium maculatum), yellow starthistle (Centaurea solstitalis), Canada thistle (Cirsium arvense), and Scotch thistle (Onopordum acanthium). Teasel, shown in the picture, is another exotic. Teasel is an Old World plant whose spiky, dried flower heads were used to comb wool before spinning.

Sources:

Whitman Mission National Historic Site: General Management Plan, September 2000. U.S. Department of the Interior, National Park Service.

Marcus and Narcissa Whitman and the Opening of Old Oregon. Clifford M. Drury.1986. Northwest Interpretive Association, Seattle, Washington.