Welted Thistle - Carduus crispus

Tall hairy plant to 2 metres, stems branched and spiny winged, except just below the flowerheads. Leaves oblong to lanceolate, pinnately lobed, weak spined. Flowerheads reddish purple, 10 to 25 mm erect, solitary or in small clusters. Flower bracts slightly spreading or erect with a weak spine tip.

Carduus tenuiflorus.  Creeping Thistle or Marsh Thistle can look similar - check the pappus hairs if in doubt.

As with all Carduus, the pappus-hairs (the silky white hairs attached to the seed - the thistledown) are not feathery or branched, but simple.  The stems have spiny wings, continuous all the way to just below the flower-head.  C tenuiflorus has a narrow, almost cylindrical flowerhead; C crispus is rounded.

ID Guide to Common Thistles

A photograph of the whole plant, including stem as well as flower heads.

Often damp grassland, stream sides.

June to August.

Biennial.

Widespread and common in lowland Britain north to the Moray Firth.

Very common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 604 of the 617 tetrads.