2018 Expedition to Honshu
From 12-28 September, 2018, Michael Dosmann and Stephen Schneider reintroduced the Arnold Arboretum to Japan on their expedition to Honshu. They were joined by Anthony Aiello (Morris Arboretum) and Todd Rounsaville (Polly Hill Arboretum), and in-country teammates Mineaki Aizawa (Professor of Forestry at Utsunomia University) and his graduate student Tatsuhiko Shibano. The Arboretum last conducted a full-fledged trip to Japan in 1977. This expedition also marked the Arboretum’s first as a member of the Plant Collecting Collaborative, an organization much like the North America-China Plant Exploration Consortium (NACPEC), but with a broader geographic scope.
Armed with a target taxa list of mutual interest to all of the gardens, Professor Aizawa led the team to collecting sites in central and western Honshu, most of which were long-term research forests of Utsunomia University, as well as University of Tokyo, and University of Hokkaido. All told, the team made some 58 collections of 55 taxa. Acer was the most common, with eight species collected; six Rhododendron; and five each of Enkianthus and Hydrangea. Additional notables included Stewartia monadelpha and S. pseudocamellia from steep mountain slopes, Sciadopitys verticillata from rain-drenched forests, and Cercidiphyllum magnificum—the rather elusive katsura species sister to the commonly planted C. japonicum.