Its collection of specimens numbers over 320 000, making it the third largest university herbarium in the Southern Hemisphere. The collection is highly representative of the Cape Flora and also houses many type specimens. The international herbarium abbreviation BOL is used when referring to the Bolus Herbarium.
Dr. Harry Bolus (1834-1911), a rich Cape Town businessman, began his collection in 1865 in Graaff-Reinet, and it is now the oldest functioning herbarium in the country. After his death, the South African College (which changed its name to the University of Cape Town on April 2, 1918) inherited his herbarium; a library featuring many expensive, unique, and rare books on botany; and a substantial amount of money for the maintenance and expansion of the collection. In 1924, a dedicated building was erected for the herbarium in Kirstenbosch, but it proved unsuitable later. Therefore, the herbarium was moved onto the campus in 1938. Dr. Lulu Bolus, Harry's niece, was also involved with the herbarium until her death in 1970.
Botanical and ecological research at the herbarium runs the gamut. The focus is primarily on Cape Province flora, including their taxonomy, invasive plants, biogeography, systematics, and evolution. Scientists from around the world conduct research here.
The best-known of the several collections of plants in the herbarium are Harry Bolus's set of orchids and heaths, Dr. H.M.L. (Lulu) Bolus's Mesembryanthemum, Dr. Augusta Vera Duthie's fungi, and Henry Georges Fourcade's trees from the area between Humansdorp and George.
Between 1915 and 1928, 4 editions were published of the Annals of the Bolus Herbarium. Later, Contributions from the Bolus Herbarium appeared.
- Floyd, K.B. "The Bolus Herbarium. University of Cape Town." Lantern, tydskrif vir kennis en kultuur. Yearbook 23, no, 1, September 1973.
- Standard Encyclopaedia of Southern Africa, several vol. Cape Town: Nasou. 1970–1976.
- "The Bolus Herbarium, Global Plants on JSTOR". plants.jstor.org. Retrieved 2018-09-14.