The herbarium of Willard Nelson Clute is housed in the Friesner Herbarium (BUT). Clute, co-founder of the American Fern Society, was a staff member at Butler University in the 1920's and 30's. His collection of ferns and fern allies from the tum of the century is significant for its selected regional coverage and for type specimens of taxa described by Clute and other fern specialists of the day.
Dolan, Rebecca W., "The Clute holotypes and the herbarium of Willard Nelson Clute in the Friesner Herbarium of Butler University" (1994). Scholarship and Professional Work - LAS. Paper 136.