''Cirsium palustre'', the marsh thistle or European swamp thistle, is a herbaceous

biennial Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years. In particular, it can refer to: * Biennial plant, a plant which blooms in its second year and th ...

(or often

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 wid ...

)

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in 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 ...

. ''Cirsium palustre'' is a tall

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 ...

which reaches up to in height. The strong stems have few branches and are covered in small spines. In its first year the plant grows as a dense rosette, at first with narrow, entire leaves with spiny, dark purple edges; later, larger leaves are lobed. In the subsequent years the plant grows a tall, straight stem, the tip of which branches repeatedly, bearing a candelabra of dark purple flowers, with purple-tipped bracts. In the northern hemisphere these are produced from June to September. The flowers are occasionally white, in which case the purple edges to the leaves are absent. The plant provides a great deal of nectar for

pollinators A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are the maj ...

. It was rated first out of the top 10 for most nectar production (nectar per unit cover per year) in a UK plants survey conducted by the AgriLand project which is supported by the UK Insect Pollinators Initiative. It is native to

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

where it is particularly common on damp ground such as marshes, wet fields, moorland and beside streams. In

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 territori ...

, it is an

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

that has become invasive. It grows in dense thickets that can crowd out slower growing native plants.Flora of North America, European swamp or marsh thistle, cirse ou chardon des marais, ''Cirsium palustre'' (Linnaeus) Scopoli
/ref>

Ecology

''Cirsium palustre'' is broadly distributed throughout much of

and eastward to central

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

. This thistle's occurrence is linked to the spread of human agriculture from the mid-

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

era or before.C. Michael Hogan. 2009
''Marsh Thistle: Cirsium palustre'', GlobalTwitcher.com, ed. N. Strömberg
It is a constant plant of several

fen-meadow A fen-meadow is a type of peatland, common in North America and Europe, that receives water from precipitation and groundwater. Habitat The continuous flow of mineral-rich and nutrient-poor acidic groundwater through fen-meadow topsoil fosters ...

plant associations, including the ''Juncus subnodulosus''-''Cirsium palustre'' fen-meadow. The flowers are visited by a wide variety of insects, featuring a generalised

pollination syndrome Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic (wind and water) or biotic, such as birds, bees, flies, and so forth through a process c ...

. Image:Cirsium_palustre.jpg

References

External links

Photo of herbarium specimen at Missouri Botanical Garden
{{Taxonbar, from=Q659846 palustre Flora of Europe Flora of Asia Plants described in 1753 Taxa named by Carl Linnaeus