This chapter examines Africans as providers of plants and local medical knowledge in Sierra Leone by focusing on the documentation produced by Adam Afzelius and Thomas Winterbottom, an English physician. It shows that, in Sierra Leone, the indigenous knowledge collected by Europeans was completely provided by Africans. Two local men, Peter and Duffa, clearly stand out among African informants. They provided more than half of the plants studied by Afzelius, and a typical entry in the botanist’s journal usually began thus: ‘Peter and Duffa brought…’ Yet, the journal remains silent on who Peter and Duffa really were. Typical of scientific voyagers, Afzelius and Winterbottom rarely discussed the identities of their assistants and informants. Although they accepted and valued African botanical and medical knowledge, their informants remain almost anonymous and completely faceless. Yet, the African contribution was integral to early modern natural history and provided the basis for the scientific studies conducted by Afzelius and his students.