Alternate name: Bristle Thistle, Nodding Thistle, Nodding Plumeless-thistle

Family: Asteraceae, Aster view all from this family

Description Introduced. Nodding, dark pink to rose-purple (rarely white), thistle-like, rayless flower heads along a long stalk at end of main stem and its branches; stem sometimes with a cobweb-like covering.
Flowers: Head 1 1/2-3"" (4-7.5 cm) wide; bracts prickly, broad, pointed, purple, outer ones curving outward.
Leaves: To 10"" (25 cm) long, lanceolate, deeply lobed, very spiny, with bases extending up and down stem as prickly wings.
Fruit: Seed-like, with long, white, minutely barbed bristles.
Height: 2-9' (60-270 cm).

Flower June-October.

Habitat Roadsides, waste places, fields, pastures, and rangelands.

Range Throughout much of North America, except far north; common in Rocky Mountain region.

Discussion This ferociously spiny, European introduction has spread rapidly. It is considered a noxious weed in several states, since cattle may refuse to graze where it grows densely and it can crowd out native vegetation. Although very similar, this species differs from the closely related Cirsium thistles in lacking white matted hairs on the leaves and in having outward-pointing bracts around the flower heads.