Alchemilla monticola Opiz (ROSACEAE)— Butler County: Slippery Rock University campus, edge of a wooded, grassy, gravel base slope on the south side of Patterson Hall; 41u03.6639N, 080u02.8889W; elevation ca. 428 m; 5 June 2009. J. Chmielewski 3208 (SLRO). Significance. This is the first collection of Alchemilla monticola (hairy lady’s mantle) from Pennsylvania. This introduced, herbaceous perennial has escaped cultivation and become naturalized in fields, lawns, roadsides, and waste places in parts of eastern and arctic North America, including Newfoundland, Nova Scotia, Quebec, and Ontario in Canada, and Alaska, Connecticut, Maine, Massachusetts, New York, and Vermont in the United States (Magee and Ahles 1999; United States Department of Agriculture, Natural Resources Conservation Service 2009). The naturalized population of A. monticola was observed on a woody, grassy slope on the Slippery Rock University campus in Butler County in the summer of 2008. The population consisted of a dozen flowering shoots, which grew in association with Aruncus dioicus (Walter) Fernald, Leucanthemum vulgare Lam., Penstemon digitalis Nutt. ex Sims, Potentilla simplex Michx., and Tussilago farfara L.