Foothills to subalpine. Meadows, rocky knolls. Summer.
Prairie Dog Knoll, Abajo Mountains, Utah, July 10, 2007.

Potentilla pensylvanica is a highly variable species, uncommon in the Four Corners area.  There is disagreement on a number of its characteristics and on its habitat.  Depending on which authority one looks at, the plant is said to grow from two to twenty inches tall.  It can be decumbent or erect, glandular or not, coarsely toothed to narrowly lobed, etc.  There is not even agreement on what elevations it is found at: Intermountain Flora states that it grows at subalpine and alpine elevations; Utah Flora has it from Sagebrush to upper montane; and Weber has it from "moist bottomlands to ... alpine ridges".  The photos show it at 10,000 feet on a rocky, treeless knoll.  Leaves are mostly basal and flowers are small, clustered, and yellow.  It is a handsome plant no matter how confused botanists are by it.

Linnaeus named the species in 1767 from a specimen collected in Canada.  The plant is not found in Pennsylvania and the reason for the name is not known.

Foothills to subalpine. Meadows, rocky knolls. Summer.
Prairie Dog Knoll, Abajo Mountains, Utah, July 10, 2007.

Foothills to subalpine. Meadows, rocky knolls. Summer.
Prairie Dog Knoll, Abajo Mountains, Utah, July 10, 2007.

Montane. Moist meadows. Summer.
Lone Mesa State Park, July 9, 2008.

This tiny Potentilla is difficult to find because it buries itself in the greenery of wet meadows.  It has deeply cut basal leaves, few stem leaves, and flower stems grow from four to eight inches long.  Sepals and leaves are hairy.  P. plattensis is found in strangely scattered populations in the Rocky Mountain states and perhaps this distribution is due to the difficulty in finding the plant.  There are a few populations in northern North Dakota, rare occurrences in southern Montana, common occurrences in the mountains of Wyoming, and scattered occurrences in a few counties of Utah, Arizona, and Colorado.  The plant has not been found before in the Four Corners area.

The plant was first collected for science by Thomas Nuttall on the "Plains of the Platte" (quotation from Intermountain Flora), probably on his western 1834-1837 trip with the Wyeth Expedition.  Nuttall named the plant in 1840.

Montane. Moist meadows. Summer.
Lone Mesa State Park, July 9, 2008.