Rubus rosarius is a rare North American species of brambles in the rose family. It has been found only in the States of Maryland, Delaware, and Virginia in the eastern United States.Biota of North America Program 2014 county distribution mapBailey, Liberty Hyde 1943. Gentes Herbarum; Occasional Papers on the Kinds of Plants 1(5): 268, figures 121–122
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
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