''Rubus sewardianus'' is a rare North American species of

brambles A bramble is any rough, tangled, prickly shrub, usually in the genus ''Rubus'', which grows blackberries, raspberries, or dewberries. "Bramble" is also used to describe other prickly shrubs, such as roses (''Rosa'' species). The fruits inclu ...

in the

rose family Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are '' Alchemilla'' (270), ''Sorbus ...

. It has been found only in the state of

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...

in the eastern United States.Fernald, Merritt Lyndon 1945. Rhodora 47(557): 154–156, plates 894–895
includes photos of type specimen at Harvard University Herbaria 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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References

sewardianus Plants described in 1945 Flora of Virginia {{Rubus-stub