Bergius was a disciple of Linnaeus, and a dedicated botanist, concentrating on the Cape flora. Like Linnaeus, Bergius obtained many of his specimens from other botanists like many of the famous Linnaean "apostles", from East India Company travellers - especially Michael Grubb, and others. The Bergius Herbarium was further enriched after Bergius' death by professors Olof Swartz and Emanuel Wikström, and thus includes collections up to the 1830s. There are also important collections of F. Hasselquist, P. Kalm, J. G. König, C. Linnaeus, P. Löfling, P. Osbeck, P. S. Pallas, D. Solander, P. Sonnerat, O. P. Swartz, A. Thouin, and C. P. Thunberg.
The Bergius Herbarium is one of the largest 18th century herbaria in Sweden with more than 17 000 sheets and resides in the Bergius Botanic Garden.
Besides the historical collections, the Bergius Herbarium holds separate collections of cultivated plants and Scandinavian vascular plants, together ca 75 000 sheets.
These collections are available only to visiting scientists.