Cirsium tuberosum can be identified by its cottony stems, twice pinnatifid leaves with only sparse hair covering, and its broad, partly spreading phyllaries, topped by very short spines.
Common name:
Tuberous thistle
Family:
Scientific name:
Cirsium tuberosum
Main flower color:
Range:
Southern England, especially in Wiltshire and Dorset
Height:
Up to 60 cm
Habitat:
Calcareous grassland
Flowers:
Solitary flowerheads, at the top of the unbranched, unwinged, cottony-hairy stem. Numerous deep pink florets above an egg-shaped involucre ringed by triangular phyllaries, relatively broad at the base, and with only very short, weak spines at the tip. Upper phyllaries are appressed, those lower down are spreading
Leaves:
Once or twice pinnatifid; divided into a small number of relatively broad segments, dark green on both surfaces, with a sparse covering of cottony hairs - equally hairy on both sides. Segments terminate in a pale yellow spine, and their edges are lined by weak bristles
Season:
June to July
Rarity:
★★★★★
