Marsh Thistle - Cirsium palustre

Medium to tall plant to 1.2 metres, stems spiny-winged to the top, sometimes branched above. Leaves linear lanceolate, pinnately lobed and very spiny, mostly unstalked, hairy above. Flowerheads usually purple, 10 to 12 mm in clusters of 2 to 8. Flower bracts purple tinged, erect, weakly spiny.

Welted Thistle (Carduus crispus) - but check the pappus hairs

Stem spiny all the way up.  As with all Cirsium, the pappus-hairs (the silky white hairs attached to the seed - the thistledown) are individually feathery or branched.

ID Guide to Common Thistles

A photograph of the whole plant, showing stems and leaves as well as flowers

Wet habitats, woodland clearings, wet ditches and marshes.

July to September.

Biennial.

Common throughout Britain.

Quite common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 379 of the 617 tetrads.