Belgian railway engineer and dendrologist who collected plants in China. Joseph Hers lived in China for several years, being based in the north-central provinces from 1919-1924. Here he collected many plants on behalf of Harvard University's Arnold Arboretum, meanwhile working as an administrator for the Lunghai Railway company. His interest in trees was partly connected to this work, for he was challenged to find suitable timber for sleepers. With this in mind he spent as much time as he could exploring forests in Henan, Jiangsu, Shaanxi and Gansu. Some of his most significant collections came from the mountain ranges of western Henan. Hers was struck by the speed of deforestation in China at that time, noting with regret how many species he was unable to relocate from year to year due to logging. He nevertheless gathered material from more than 2,000 different species, many of which were new to science. His collections led to horticultural introductions, too, such as the snakebark maple Acer tegmentosum Maxim. subsp. hersii (Rehder) A.E.Murray (originally named Acer hersii Rehder in his honour) and Celtis koraiensis Nakai.

Sources:
J.H. Barnhart, 1965, Biographical Notes Upon Botanists, 1: 165
E.H.M. Cox, 1945, Plant Hunting in China: 208-209.