Correspondence, including some plant determinations and receipts from:
- Dr. G. Claridge Druce - 12 letters
- William Wright Smith - 5 letters including Hayward's obituary for the Linnean Society, published in 1950
- Isaac Bayley Balfour, Royal Botanic Garden Edinburgh - 3 determinations/receipts
- Arthur W. Hill, Royal Botanic Gardens, Kew - 2 determinations/receipts
- E.W. Marquand - 2 letters
- A. Bruce Jackson, Kew - 3 letters
- Charles Lapworth - 3 letters regarding the British Association
- A. Thellung, Zurich - one letter in French
- William Watson[?] - one list of determinations
- Clement Reid - 3 letters found in a copy of a book presented by him to Miss Hayward