Similar species:
Plumeless Thistle (Carduus acanthoides) - Very similar; flower head smaller and stalk not smooth. Bull Thistle (Cirsium vulgare) - Much larger, flower head not nodding.
Nodding Thistle flower head. Note that it is indeed "nodding".
ALso note that the stalk immediately below the flower head is usually smooth, but not always.
Nodding Thistle flower head atop its stalk. Notice the purple-coloured bracts just below the flower head.
Side view. This particular flower stalk is an exception in that it is not smooth just below the flower head.
Head-on view of the flower head.
Nodding Thistle flower head in bud.
Nodding Thistle stem - note that it is very prickly.
Nodding Thistle plant.
Nodding Thistle plant in winter.
Nodding Thistle going to seed. The seeds are readily dispersed by the wind.
PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.
(Range map provided courtesy of the USDA website
and is displayed here in accordance with their
Policies)