- More than 800,000 type specimens;.
- Over 175,000 scientific research articles and other content dating back hundreds of years from leading academic journals including Kew Bulletin, Mycologia, International Journal of Plant Sciences, Science, PNAS, and others;
- Foundational reference works and books such as The Useful Plants of West Tropical Africa, Flowering Plants of South Africa, and illustrations from Curtis's Botanical Magazine;
- A significant set of correspondence, including Kew’s Directors' Correspondence which included hand-written letters and memorandum from the senior staff of Kew from 1841 to 1928;
- More than 20,000 paintings, photographs, drawings, and other images.
It is especially useful for anyone interested in botany, biology, ecology, environmental and conservation studies.