''Cirsium andrewsii'' is an uncommon 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 name Franciscan thistle. It 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 ...

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 ...

, where it is known from the coastline of the

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

from

Marin Marin (French) or Marín (Spanish "sailor") may refer to: People * Marin (name), including a list of persons with the given name or surname * MaRin, in-game name of professional South Korean ''League of Legends'' player Jang Gyeong-hwan (born 19 ...

to San Mateo Counties.Flora of North America
/ref> There are also reports of isolated populations in the Klamath Mountains and in 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 primarily ...

.Calflora taxon report, University of California, ''Cirsium andrewsii'' (A. Gray) Jepson, Franciscan thistle
/ref> ''Cirsium andrewsii'' grows in coastal habitats such as sea bluffs and canyons, and is sometimes found on

serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially anti ...

s. The species is biennial to

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 ...

, producing an erect, leafy stem which can reach two meters in height. It is highly branched, dense to clumpy, fleshy, and cobwebby with fibers, especially when new. The leaves are woolly or cobwebby, spiny along the edges, and sometimes lack lobes or deep cuts. They are borne on petioles with winged, spiny margins, some spines exceeding a centimeter in length. 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 ...

produces 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 3 centimeters long by 5 wide, wispy with cobwebby fibers, and lined with very spiny phyllaries. The flower head is packed with dark purplish-pink flowers up to about 2.5 centimeters in length. 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 ope ...

with a dark brown body about half a centimeter long and a pappus about 1.5 centimeters long.

References

External links

Jepson Manual TreatmentThe Nature ConservancyCalphoto Photo gallery, University of California
andrewsii Endemic flora of California Natural history of the California chaparral and woodlands Natural history of the San Francisco Bay Area Plants described in 1874 Critically endangered flora of California {{Cynareae-stub