''Rubus exsularis'', the fenceline dewberry, is a rare North American species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

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 in the northeastern and north-central United States, primarily in the Appalachian Mountains from New York to

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...

, with a few isolated populations in southeastern

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

. 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

exsularis Plants described in 1943 Flora of the Eastern United States {{Rubus-stub