Business man and founder-member of the Philadelphia Botanical Club, Leeds was chiefly interested in ferns. In 1928 he began the organization of the Academy's herbarium of Pteridophyta, which he continued until his death. His personal herbarium and his library were bequeathed to the Academy. These papers consist of (1) A field notebook 1924-36, containing addresses of his correspondents and long lists of numbered entries to plants, sometimes with the scientific name only, sometimes with additional information about geographical distribution and often with the type of ecology indicated (2) Loose pages from a small notebook with similar entries but also with additional miscellaneous notes about specimens in other collections, about early botanists and some addresses (3) Diary and loose notes of his 1936 collecting trip to Georgia and the Carolinas.