Rubus severus is an uncommon North American species of flowering plant in the rose family. It is found in eastern Canada (Nova Scotia) and the northeastern and north-central United States (Maine, Vermont, New Hampshire, Rhode Island).Biota of North America Program 2014 county distribution mapFernald, Merritt Lyndon 1931. A new blackberry from New Hampshire. Rhodora 33(388): 102–104 description in Latin, commentary in English
The genetics of Rubus is extremely complex, so that it is difficult to decide on which groups should be recognized as species. There are many rare species with limited ranges such as this. Further study is suggested to clarify the taxonomy.Flora of North America, Rubus Linnaeus, 1754. Bramble Some studies have suggested that R. severus may have originated as a hybrid between R. setosus and R. flagellaris. Flora of North America, Rubus setosus Bigelow, 1824. Bristly blackberry, ronce sétuleuse
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