P. Rodney Thompson
Director


Address:

 

829 South Coleman
Tooele, UT 84074

Telephone Number:


Main: (435) 843-3204

 

Hours:

7:00 am - 6:00 pm
Monday - Thursday
Except Holidays
Closed Fridays

Weed Control Division - Noxious Weeds


 

Scotch Thistle
(Onopordum acanthium L.)


Growth Habit:
Biennial, sometimes annual, erect, up to 8 feet tall. Rosette formed first year, flowering stem elongates second year.

Leaves:
Large, coarsely lobed, hairy on both sides, velvety gray appearance. Margins lined with sharp conspicuous spines. Basal leaves up to 2 feet long and 1 foot wide.

Stems:
Erect, branching, spiny leaf wings extend down onto stem, covered with dense fine hairs.

Flowers:
Solitary, terminal, 1 to 2 inches in diameter, violet to reddish colored. Bracts spine tipped.

Roots:
Large fleshy taproot.

Seeds:
Deep brown to black, distinctly wrinkled, 3/16" long.

Other:
Reproduce by seed only. Dense strands may be impenetrable to recreationists, livestock or wildlife.
Quackgrass

Return to Noxious Weed page.

 

 

Tooele County | 47 South Main Street | Tooele, UT 84074 | Telephone: (435) 843-3100