The Herbarium was established by Dr. A.A. Wellwood as a teaching resource to be used as support for the Systematic Botany course. The Herbarium consists of over 15000 vascular plant collections. In addition, there is a bryophyte and lichen collection of over 3000 specimens.
Over the years, the University has contributed considerable resources in the form of student help to enable preparation of the sheets, primarily of Southern Ontario flora. A significant part of the Herbarium is Dr. A.A. Wellwood's Perth County survey. This collection is the result of many years of collecting by Dr. Wellwood and student assistants and represents the most complete assemblage of specimens from Perth County in existence. Although small by the standards of other university herbaria, the completeness of the local and regional flora makes this a valuable collection for both research and teaching purposes.
Other research collections housed in the Herbarium include those of Dr. D.Weber, Dr. T.T. McIntosh, Dr. W.Y. Watson, and Dr. T. Beechey. The Herbarium is used by faculty and students as well as outside researchers. Material is frequently exchanged with other universities and botanical gardens.