Plumeless Thistle

 

Common name: Plumeless Thistle

 

Growth form: Forb

 

Life Span: Biennial (or winter annual)

 

Origin: Eurasia

 

Flowering Dates: June-August

 

Reproduction: Seeds

 

 

Height: 0.3 - 1.5 m (1 - 4.9 ft, usually 3 - 4 ft.)

 

Flower: Purple, rarely white or yellow (1.4 - 2 cm long)

 

Fruit: Achene, slightly obovate to oblong (2.5 - 3 mm long), somewhat quadrate, a little compressed, straw - colored to light brown, ribs 10; pappus of numerous, minutely barbellate bristles, forming a ring; 1 - seeded

 

Seed: Enclosed in the achene, small

 

Leaves: Alternate; blades simple; cauline leaves sessile, decurrent, elliptic to lanceolate or oblong (10 - 20 cm long), irregularly and deeply pinnatifid with spinulose lobes, segments 1 - to - 4 pointed, marginal spines 1 - 6 mm long, surfaces pubescent; rosette leaves similar except less deeply pinnatifid and less hairy on upper surface

 

Stems: Erect, freely branching above, with spiny wings (3 - 15 mm wide), densely hairy to nearly hairless

 

Underground: Taproot, stout, fleshy

 

Where Found: Primarily in the northeastern portion of Nebraska in pastures, rangeland, and other noncropped areas

 

Uses and Values: Plumeless thistle is an important plant for butterflies. Its seeds are eaten by numerous species of songbirds

 

Poisoning: Plumeless thistle may accumulate nitrates, but it is unpalatable to livestock

 

Other: Plumeless thistle is an aggressive weed and is similar to the closely related musk thistle (Carduus nutans). Plumeless thistle is a noxious weed in Nebraska and many other states. It rarely flowers the first year.