Cirsium palustre

Cirsium palustre, the marsh thistle or European swamp thistle, is a herbaceous biennial (or often perennial) species of the genus Cirsium.

Cirsium palustre is a tall thistle which reaches up to 2 metres (7 ft) 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, 10–20 millimetres (0.4–0.8 in) 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.