Scientific Family
Asteraceae
Synonyms
Carduus lanceolatus, C. vulgaris, Cirsium lanceolatum var. hypoleucum, C. lanceolatum
Plant type
Forbs and Subshrubs
Origin
Introduced
Lifecycle
Biennial
Height
2 to 4 feet
Riparian
Yes
Biennial with prickly, winged stems; rosette leaves elliptic, coarsely toothed; stem leaves deeply lobed, taper to a point, minutely hairy above, densely matted below, prickles stout; flower heads 1 or few, at ends of short, prickly-winged branches.
Biennial, taprooted; 1 to many erect or ascending, spiny, winged stems, wings almost the full length of distance between leaves; leaf blades long, lance-shaped, very spiny; purple flowers develop at the apex and have narrow spiny, yellow-tipped bracts.
Habitat
Invasive of disturbed sites, pastures, meadows, forest openings, roadsides.
Plant Community
Riparian
Pinyon Juniper Woodlands
Montane Conifer Forest
Disturbed Areas
Low elevation
5000
High elevation
7000
Flower Characteristics
The purple flower heads are 1-1/2 to 2 inches in diameter and 1 to 2 inches long with narrow, spine-tipped bracts in 10 to 12 overlapping series; bracts not sticky on their outer surface.
Flower color
Purple, rarely white
Flower shape
Daisy or dandelion-like
Tubular
No
First bloom month
August
Last bloom month
October
Flower clusters
None
Leaf and Stem Characteristics
Leaves are 3 to 12 inches long, lance-shaped, coarsely lobed and covered in sharp spines.
Leaf type
Simple
Leaf color
Green above, gray below
Leaf shape
Pinnatifid
Leaf margin
Lobed
Leaves clasp
Yes
Leaf hairs
Leaves & stems
Spines
Yes
Fruit and Seed Characteristics
Seed-like fruit, about 1/5 inch long, elongated and tipped with numerous bristles.
Fruit type
Achene
Fruit color
Light brown with dark streaks
Flower heads produce hundreds of seeds.