Cursium vulgare
Bull Thistle
Common Thistle
Identification
Bull Thistle is distinguished from other thistles by the
following characteristics. Leaf blades, especially those that
are larger and deeply lobed, are rough to the touch like
medium sandpaper and dark green. Stems of bolted plants
appear winged because leaf blades continue along the
petioles and several inches down the stems. Flowerheads
are one to two inches wide and one and a half to two and a
half inches high with deep purple flowers. The bristles on
the pappus (thistledown) are feathery. This characteristic
Mature Plant of Bull Thistle
distinguishes thistles in the genus Cirsium from those in
the genus Carduus, which have unbranched, thread-like
bristles.
Origin
First introduced to the United States and Canada in the
early 1600s, by French settlers as a contaminant in crop
seeds; by 1954 has been declared a noxious weed in forty
three states.
Facts
Infestation of Bull Thistle
Sierra Valley
Sierra Valley Resource Conservation District
Po Box 3562
Quincy, CA 95971
www.sierravalleyrcd.com
E: sierravalleyrcd@gmail.com
P: 530-283-0455

Habitat: Meadows, roadsides, disturbed areas

Life Cycle: Biennial

Flowering Time: Mid- July to Fall

Spread: Seeds

Height: 1- 6 feet, commonly 2- 3 feet

Noxious Weed List: California C-rated
Cirsium vulgare
Bull Thistle
Common Thistle
Why is it a threat to Sierra Valley?

Invasive and displaces native plant species

Unpalatable and interferes sufficiently with
livestock grazing lands

Colonizes and maintains high population
densities for up to six years
Think you may have this invasive
weed or seen one?

Please contact your local Resource
Conservation District.
Sierra Valley RCD
Po Box 3562
Quincy, CA 95971
(530)283-0455
Project Manager 775-722-2610
sierravalleyrcd@gmail.com

A member of the staff will come identify the
plant and record the weed’s location.

District staff will work with you to determine
the best method of control that fits your
property and the invasive weed’s present.
With your permission, the District will monitor
the site after control measures are completed
to ensure control efforts succeeded.
Description

Flower: In clusters at ends of branches

Flower Color: pink to purple

Stem: Spiny and winged

Leaves: Sandpaper texture, prominent
veins
“NOXIOUS WEED CONTROL
DEPENDS ON YOU.”