Collection date: 1860-61. Permanently transferred to WIS in 1982. This collection consisted largely of specimens donated by or purchased from Mr. S. H. Watson, whose collections were made in southern Wisconsin from 1859-1862. The Watson collection contains some specimens received from fellow Wisconsin botanist T. J. Hale and a few other collectors, including I. A. Lapham, D. C. Eaton, S. B. Mead, and M. H. Clark.