State Noxious Weed List - No

Growth form: Plumeless thistle is a winter annual or biennial forming rosettes in late-summer and bolting in early spring. The stems are winged and very branched giving the plant a candelabrum appearance.

Flower heads are small (0.5 to 1 inch) but very numerous. The bracts are very narrow and resemble spines.

The plant is spread only by seed.

Rosettes of plumeless thistle resemble musk thistle rosettes, but are more deeply lobed and much more pubescent. The plant bolts in late-April to early May and will grow 4 feet or more in height.

Plumeless thistle can become very weedy and form dense colonies, especially along waterways, ditches, and roadsides.

The wings are very spiny and are continuous along the stem. The leaves are deeply lobed, narrower than musk thistle, and very pubescent underneath. Each lobe has one to three very sharp marginal spines.