Slender thistles

Carduus tenuiflorus, Carduus pycnocephalus

Slender Thistle is a spiny, erect, purple flowered annual to biennial thistle, usually about 1 m tall, with clusters 1-3 flower heads that are 10-15 mm wide. The stems have discontinuous wings that are spiny and no wings on the 100 mm of stem below the flowers. The seeds have about 20 ribs and the bristles topping the fruits are only very minutely barbed. The leaves have spiny lobes a cobweb-like hairs.

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