Pictorial guide to the flora of the British Isles

Home ⟩ Pictorial Guide ⟩ Asteraceae / Compositae ⟩ Carduus pycnocephalus / Plymouth thistle

Carduus pycnocephalus L.

Plymouth thistle (Asteraceae / Compositae)

 SpreadBias within British IslesDirection of bias
Very localModerate tendencySE
Plant Atlas 2020
BSBI Distribution Map

Carduus pycnocephalus is a southern European thistle that has been naturalised on Plymouth Hoe (VC3: South Devon) since 1868, and occasionally appears as a casual elsewhere.

Plymouth (VC3: South Devon); 2021-06-02

 Plymouth thistle / Carduus pycnocephalus: _Carduus pycnocephalus_ is a southern European thistle that has been naturalised on Plymouth Hoe (VC3) since 1868, and occasionally appears as a casual elsewhere.

Carduus pycnocephalus has narrow capitula, like Carduus tenuiflorus, but has incomplete wings along the stem, especially above, lacks the membranous phyllary-margins, and has a denser covering of cottony hairs on the stems and leaves.

Plymouth (VC3: South Devon); 2021-06-02

 Plymouth thistle / Carduus pycnocephalus: _Carduus pycnocephalus_ has narrow capitula, like _Carduus tenuiflorus_, but has incomplete wings along the stem, especially above, lacks the membranous phyllary-margins, and has a denser covering of cottony hairs on the stems and leaves.

All images copyright © Christopher J. Dixon unless otherwise indicated.

L-R: Bidens tripartita, Melilotus officinalis, Mimulus guttatus, Thalictrum flavum, Ranunculus peltatus, Anchusa arvensis, Malva alcea, Lolium perenne