Plumeless thistle

Carduus acanthoides

Plumeless thistle can be distinguished from musk thistle by the leaf-like spines on the stem, and hairs on the underside of the leaf
Plumeless thistle flower heads are 1-2 in wide, about one-third the size of musk thistle flower heads

Lifecycle: Winter annual or biennial
Growth form: Forb
Flower: Flower heads are solitary at the ends of branches or in clusters of 2-5. Flower bracts are narrowly lance-shaped and appear as sharp spines. Flowers are purplish-pink and clustered in heads that are 1-2 in wide.
Seeds/Fruit: One-seeded fruit (achene), capped by a ring of bristles.
Leaves: Basal rosette leaves are usually 4-8 in long with spiny lobes. Stem leaves alternate, stalkless, hairy underneath, and blending into the stem.
Stems: Mature plants are between 1-4 ft tall. Stems are freely branched above and covered with leaf-like spines that extend up to the flowering heads.
Roots: Thick, fleshy taproot.
Other: Closely related to musk thistle (Carduus nutans).

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