''Cirsium longistylum'', the long-style thistle, is a
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 ...
n species of plants in the tribe
Cardueae
The Cardueae are a tribe of flowering plants in the daisy family (Asteraceae) and the subfamily Carduoideae. Most of them are commonly known as thistles; four of the best known genera are '' Carduus'', '' Cynara'' (containing the widely eaten ar ...
within the family
Asteraceae
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
. The species is found only in the central part of the State of
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 ...
in the
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 ...
, in the portions of the
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
called the
Big Belt,
Castle
A castle is a type of fortified structure built during the Middle Ages predominantly by the nobility or royalty and by military orders. Scholars debate the scope of the word ''castle'', but usually consider it to be the private fortified r ...
,
Elkhorn, and
Little Belt ranges.
[Flora of North America, Long-style thistle, ''Cirsium longistylum'' R. J. Moore & Frankton]
/ref>
''Cirsium longistylum'' is a biennial or perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
herb up to 150 cm (60 inches or 5 feet) tall, with a large taproot. Leaves are up to 30 cm (26 inches) long with thin, green on the upper side but gray to white on the underside because of numerous woolly hairs; spines along the edges of the leaves. There are a few 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 head with white disc floret
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
s but no ray florets. The name of the species refers to the long white styles that stick out of the florets, much longer than the corollas.[Moore, Raymond John & Clarence Frankton. 1963. Canadian Journal of Botany 41(11): 1562–1563, plate 1]
References
External links
Montana Field Guide
description, ecological and conservation information, color photo, distribution map
Wildflowers of the United States
photos
longistylum
Flora of Montana
Plants described in 1963
{{Cynareae-stub