The collection, including a number of valuable type specimens, is comprised mainly of species collected in the Northern Cape.

Most of these samples were accumulated along the Vaal river, from the area north of the Orange river and in areas around Kimberley that are now developed. Many of them are therefore irreplaceable.

Special collections include specimens collected by J.P.H. Acocks, Maria Wilman for her book Preliminary Checklist of the Flowering Plants and Ferns of Griqualand West, A.A. Gubb for a vegetation map of the Northern Cape, and rare and threatened plants of the Northern Cape collected during research on their conservation status. Collecting trips to expand the collection are now aimed at areas that are under-represented or where plants have not been previously collected.

Herbaria are important storage and retrieval systems for plant-related data. This raw data forms the basis of many fields of plant research, where the first step is usually the correct identification of a species. Herbaria play an important role in supplying other researchers, industry and the public with botanical information.