''Clematis occidentalis'' is a species of flowering plant in the

buttercup family Ranunculaceae (buttercup or crowfoot family; Latin "little frog", from "frog") is a family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are ''Ranunculus'' (600 species), ''Delphinium' ...

known by the common name western blue virginsbower. It is native to much of southern

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and the northern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. There are three varieties: var. ''occidentalis'' is limited to the eastern half of the species' range, var. ''grosseserrata'' to the western half, and var. ''dissecta'' is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on ...

. The plant varies somewhat in appearance. Generally they produce

vine A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themselv ...

s and climb on surfaces. The leaves are divided into three thick, green leaflets, which may have lobes or teeth. The flower has no petals, but petallike

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s which are usually either deep purple-blue in western populations or reddish purple in eastern plants. White flowers are rare.

External links

*
USDA Plants ProfileFlora of North America
occidentalis Flora of North America Plants described in 1815 {{Ranunculales-stub