diffuse knapweed

Centaurea diffusa Lam.

Description from Invasive.org

Appearance
Centaurea diffusa is a biennial, annual, or short-lived perennial that is 8-40 in. (20.3-101.6 cm) tall.
Foliage
The leaves are stalked and lobed. The leaves become smaller and less divided as they move up the stem.
Flowers
Flowering occurs from July to September. White flowers develop in urn-shaped heads, in clusters, at the ends of the branches. The heads are subtended by leathery bracts. The lower and middle bracts have brown margins with spines at the tips.
Fruit
Seeds are achenes, 0.08-0.12 in. (2-3 mm) long with a plume of bristle-like hairs.
Ecological Threat
This species prefers well drained soils, gravel pits, trails, pastures and roadsides.

Resources


Selected Images from Invasive.org

View All Images at Invasive.org


Plant(s)
Sara Rosenthal, USDA Agricultural Research Service, Bugwood.org
Additional Resolutions & Image Usage
Plant(s)
Cindy Roche, , Bugwood.org
Additional Resolutions & Image Usage
Flower(s)
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage
Flower(s)
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage
Flower(s)
USDA APHIS PPQ - Oxford, North Carolina , USDA APHIS PPQ, Bugwood.org
Additional Resolutions & Image Usage
Flower(s)
Cindy Roche, , Bugwood.org
Additional Resolutions & Image Usage
Flower(s) Close-up view of a flower head and flower bud of diffuse knapweed (Centaurea diffusa), showing the spiny bracts.
L.L. Berry, , Bugwood.org
Additional Resolutions & Image Usage
Seedling(s)
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Additional Resolutions & Image Usage
Plant(s)
Steve Dewey, Utah State University, Bugwood.org
Additional Resolutions & Image Usage

Distribution