Northern Prairie Wildlife Research Center
Found in nearly every county in North Dakota, Pennsylvania cinquefoil ranges from Greenland to Alaska, south to New Hampshire and Nevada at elevations below about 9,500 ft.
Pennsylvania cinquefoil is perennial from a branched base atop a taproot. Most North Dakota specimens are about a foot tall. Stems are sometimes simple and solitary, but more commonly several and branched. Leaves with long petioles and 5-15 leaflets arise from the base. Smaller leaves are scattered remotely along the stem. Leaves may be nearly green or silvery from a dense covering of hairs, especially underneath. All leaflets are deeply incised halfway or more to the midrib. Flowers are yellow, about 1/4 inch wide, and occur in rather compact, branched clusters. Each flower produces many tiny, ribbed seeds.
Look for Pennsylvania cinquefoil in dry gravelly or sandy native prairie. In North Dakota, a few more plants seem to occur where grazing is heavy or moderate, but this may not be true farther west. The leaves and roots of many Potentillas are used in teas and medicines, but none of the references available to me mention the species discussed here.
The cinquefoils (meaning "five-leaved") are members of the rose family (Rosaceae). Rose is an ancient Latin name. The family contains about 3,000 species, and includes dozens of horticulturally and agriculturally important plants such as mountain-ash, spiraea, pear, apple, cherry, and strawberry. The generic name Potentilla is a diminutive of potens, "powerful," originally applied to another cinquefoil for its reputed medicinal powers. The specific epithet means "of Pennsylvania" in botanical Latin, but is a misnomer, as the original collection came from the shores of Hudson Bay. Pennsylvania cinquefoil was described for science in 1767 by the Swedish father of modern botany Carl Linnaeus (1707-1778).