Payment Form

Enter the payment details and submit

Annual Dues

$125.00

Enter your details below

Spambot blocker question

9 + 10 =

Validating payment information...
Waiting for PayPal...
Validating payment information...
Waiting for PayPal...

UWSA

  • UTAH’S NOXIOUS WEEDS
  • CONTACT US
  • HOME
  • RESOURCES
    • CALENDAR
    • NEWSLETTERS
    • NEWS ITEMS
      • PROJECTS
      • NEWS
      • FEATURE ITEMS
      • SPOTLIGHT
    • UTAH WEED LAW
    • PUBLICATIONS
  • ABOUT US
    • OUR LEADERSHIP
  • FUNDING
    • GRANTS
    • GRANT APPLICATION FORMS
  • NOXIOUS WEEDS
    • UTAH WEED LISTS
    • UTAH WEED LAW
    • WEED FIELD GUIDE
    • NEW INVADERS GUIDE
  • BIOCONTROL
    • UTAH BIOCONTROL
    • BIOCONTROL FIELD GUIDE
    • AVAILABLE AGENTS
PAY ANNUAL DUES

Squarrose Knapweed

Squarrose Knapweed

BACKGROUND: Squarrose knapweed is a native plant of the eastern Mediterranean area. It is very competitive on rangelands. Knapweed releases chemical substance that reduces competing vegetation.

DESCRIPTION:This long-lived herbaceous weed has a simple taproot and grows 12 to 18 inches tall. The rosette and stems have deeply-lobed leaves. Flowers are rose to pink. It is often confused with diffuse knapweed, but differs in that the terminal spines on the flower bracts are curved outward and are not laterally toothed. Bloom occurs in the early to mid-summer.

CONTROL: Several biocontrol agents are available. Herbicides offer good to excellent control. Contact your state or county weed specialist for specific, updated information.

  • SCIENTIFIC NAME: Centaurea virgate
  • CLASS: 2
  • BIOCONTROL AGENTS AVAILABLE: YES

Related Biocontrol

Larinus minutus

BIOLOGY: Adults are active from May to September. They are…

Cyphocleonus achates

BIOLOGY: C. achates adults emerge from June to September. They…

Search for insects

Contact us with questions

Utah Biological Control

Amber Mendenhall

phone: 435 830 4146

email: utahsbuggirl@gmail.com

Utah Noxious Weeds

contact your local County Weed Supervisor

NEW INVADERS GUIDE

Other high priority (Class 1A) noxious weeds

African Rue

BACKGROUND: OTHER COMMON NAMES: DESCRIPTION: TA succulent, highly-branched herbaceous perennial,…

Common Crupina

BACKGROUND: OTHER COMMON NAMES: DESCRIPTION: A winter annual. Common crupina…

Malta starthistle

Malta starthistle

BACKGROUND: OTHER COMMON NAMES: Malta thistle DESCRIPTION: An annual or…

Mediterranean sage

BACKGROUND: OTHER COMMON NAMES: Ethiopian sage DESCRIPTION: A shrubby biennial…

Spring Milletgrass

BACKGROUND: OTHER COMMON NAMES: Spring millet DESCRIPTION: Spring milletgrass is…

Plumeless Thistle

BACKGROUND: OTHER COMMON NAMES: DESCRIPTION: A winter annual or biennial.…

Small Bugloss

BACKGROUND: OTHER COMMON NAMES: Annual bugloss DESCRIPTION: Small bugloss is…

Syrian Beancaper

BACKGROUND: OTHER COMMON NAMES: DESCRIPTION: A rhizomatous woody perennial that…

  • Utah noxious weed law
  • Newsletters
  • Cost Share Funding
  • Contact
  • Leadership

© 2023-2026. All rights reserved.

TOP