Certificates and awards including the Order of Australia Award and Willis's doctorate , Willis's last diaries, memorabilia, newsclippings collected by Willis, photographs, thankyou letters, correspondence and obituaries and other material regarding memorials and commemorative services held after Willis died, some of which are inscribed with hand written annotations and small descriptions. The 'Autobiographical Writings of J.H. Willis (1991)' includes photographs and handwritten manuscripts of significance, and two series of letters written by Jim Willis to his family while at Kew as Australian Botanical Liaison Officer.