''Cirsium andersonii'' is a North American 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 Anderson's thistle and rose thistle. It is native to

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

, Oregon, and

Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...

, where it grows in the woodlands and forest openings of the local high mountain ranges, including the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

and the southern Cascade Range. It has also been reported from

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 W ...

.Flora of North America
/ref> This native thistle is a perennial herb growing erect to a maximum height approaching . It produces one to multiple stems, simple or branching, which may be hairless to quite woolly. The deeply lobed and sharply cut leaves are borne on spiny-winged petioles, the longest toward the base of the plant reaching over long. 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 ...

bears one or more

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 ...

, each up to 5 centimeters long by 4 wide at the largest. The head is lined with spiny, purple-tipped

phyllaries In botanical terminology, a phyllary, also known an involucral bract or tegule, is a single bract of the involucre of a composite flower. The involucre is the grouping of bracts together. Phyllaries are reduced leaf-like structures that form one ...

which curve outward. The head contains many red, purplish, or rose pink flowers, each up to 4.5 centimeters long. The fruit is an

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 op ...

with a brown body 6 or 7 millimeters long topped with a pappus which may be 4 centimeters in length. The flower heads attract

hummingbird Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics ar ...

s. It was originally named ''Cnicus andersonii'' after

Charles Lewis Anderson Charles Lewis Anderson was an American medical doctor who, in addition to the practice of medicine, made important contributions to fields of natural history, especially botany. Educated in Indiana, he spent most of his professional life in the ...

Asa Gray Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botanist of the 19th century. His '' Darwiniana'' was considered an important explanation of how religion and science were not necessarily mutually ex ...

; its name was later changed to ''Cirsium andersonii'' by Petrak.

References

External links

Jepson Manual TreatmentCalphotos Photo gallery, University of California
andersonii Plants described in 1874 Flora of the Western United States Taxa named by Asa Gray Flora without expected TNC conservation status {{Cynareae-stub