| RefNo | Title | Source |
| DF/BOT/440/7 | Excell, Arthur Wallis: Correspondence and Papers | |
| DF/BOT/440/17 | Excell, Arthur Wallis (Combretaceae): Correspondence and Papers | |
| DF/BOT/440/17/1 | Drawings of Combretum specimens, all groups and all regions | |
| DF/BOT/440/17/2 | Correspondence between A W Exell and Clive A Stace, Professor Emeritus, Department of Biology, University of Leicester | |
| DF/BOT/440/17/3 | Notebooks compiled by Arthur Wallis Exell containing specimen lists for Combretum | |