David Armstrong
David Pearman
University of Bristol
P. D. Sell, Gina Murrell
C. N. Page
Robert Gordon Brabazon O'Neill Roe
Roger Phillips
Oleg Polunin
Robert Lloyd Praeger
James Walter White
Alan Mitchell (Dendrologist)
A. R. Clapham
Richard Le Strange
C. T. Prime
Morten Lange
Helmut Grünert
J. H. Elliott
M. C. F. Proctor
R. J. Murphy
P. D. Sell
Rosalind Delany
C. D. Preston
Ian P. Green