Why is it a noxious weed?
Common crupina (Crupina vulgaris) Weed.
Adapted to a wide range of soil and climate conditions, common crupina can form solid stands which decreases forage for livestock. Common crupina is also federally listed as a noxious weed.
How would I identify it?
General Description: It is a winter annual that grows up to 3 feet tall. Seeds germinate in the fall and winter when conditions are favorable. Warmer spring temperatures cause the plants to grow flowering stems that bloom in May and June and go to seed in June and July.
Flower Description: Flower heads clustered 1 to 5 on each stem, each one is thin and vase-shaped with a few rows of tapering bracts at its base. Flower head have 3 to 5 flowers and each head generally produces one seed. Flowers are lavender to purple.
Leaf Description: Basal leaves are rounded and typically not lobed, 0.4 to 1.2 inches (1 to 3 cm) long and often dying back early. Stem leaves alternate and lobed or doubly lobed, appearing lace-like with short, stiff bristles. Stem leaves up to 2.8 inches (7 cm) long.
Stem Description: Stems are rigid and have short stiff spines. Also, stems are leafy up to where it openly branches at the top.
Fruit/Seed Description: Seeds are barrel-shaped and 0.12 to 0.16 inches (3 to 4 mm) long. Brown-black bristles (pappus) occur on one end spreading widely.
Distribution Map:
Common crupina (Crupina vulgaris) Distribution in North America shown in green.
How does it reproduce?
Common crupina reproduces by seed.
Where does it grow?
Common crupina grows in a wide variety of habitats including fields, grasslands, roadsides, open woodlands and forests up to 3280 feet (1000 m)
Close up of the Common crupina (Crupina vulgaris) Weed.
elevation. Please click here to see a distribution map of common crupina in Washington.
How do I control it?
Mechanical Control:
Hand pulling or hoeing can effectively control common crupina, but regular site visits are required since it produces a large amount of viable seeds.
Biological Control:
Several natural enemies have been identified on common crupina in southern France and are under investigation as possible biological control agents. No biocontrols are currently approved for use in the United States.
Herbicide Control:
Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.
Sourced From: http://www.nwcb.wa.gov/detail.asp?weed=40
