First Report of Sphaerellopsis filum Colonizing Rust of Bird's-foot Trefoil in the United States. K. T. Leath, USDA-ARS, Regional Pasture Research Lab, Department of Plant Pathology, Pennsylvania State University, University Park 16802. R. Rodriguez, and B. W. Pennypacker. Department of Plant Pathology, Pennsylvania State University, University Park 16802. Plant Dis. 77:100. Accepted for publication 24 August 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0100D.