''Cirsium brevistylum'' is a species of

thistle Thistle is the common name of a group of flowering plants characterised by leaves with sharp prickles on the margins, mostly in the family Asteraceae. Prickles can also occur all over the planton the stem and on the flat parts of the leaves. ...

known by the common names Indian thistle and clustered thistle. It is native to western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

having been found in southwestern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

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 ...

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

, and

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. ''Cirsium brevistylum'' grows in moist areas in many types of habitat, from mountain forests to

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

and coastal

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

es. This native thistle is annual or biennial, reaching in height and known to exceed at times. There is usually a single stem which may branch toward the top and is coated in hairs and webby fibers. The leaves are deeply cut into many lobes lined with twisted teeth, the longest leaves near the base of the plant reaching about 25 centimeters long. The leaves are borne on winged petioles with many spines. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

bears one to many

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

, both at the ends of the stem branches and in the leaf axils. The flower head reaches about 3 centimeters long by 4 wide and is lined with cobwebby, bristly, spine-tipped phyllaries. The flower head is packed with white or pink flowers about 2 centimeters long. The fruit is a brown

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

a few millimeters long topped with a pappus one to two centimeters in length.Cronquist, Arthur John 1953. Leaflets of Western Botany 7(2): 25-26
/ref>

Gallery

File:Asteraceae cirsium brevistylum Indian thistle.jpg, Indian Thistle File:Cirsium brevistylum (5975948274).jpg, Cirsium Brevistylum File:Cirsium brevistylum (5975392645).jpg, Cirsium Brevistylum sometimes found in sagebrush steppe File:Cirsium brevistylum (5975949740).jpg, Cirsium Brevistylum stem

References

External links

Jepson Manual TreatmentCalphotos Photo gallery, University of California
brevistylum Plants described in 1953 Flora of the Western United States Flora of British Columbia Flora without expected TNC conservation status Taxa named by Arthur Cronquist {{Cynareae-stub