Some books by or about Ernest Wilson
Naturalist in Western China (Plant Hunter Series/2 Volumes in 1)
Plant Hunting (Volume I): v. I
Plant Hunting (Volume II): v. II
Chinese Wilson by Roy Briggs
Plantae Wilsonianae; an enumeration of the woody plants collected in western China for the Arnold Arboretum
China Mother of Gardens
Aristocrates Of The Garden
Smoke That Thunders
Online resources
Lisa Pearson, head of the Arnold Arboretum Horticultural Library and Archives has written two stories about Wilson's expeditions which you can access here