BugwoodWiki Article

Italian plumeless thistle
Carduus pycnocephalus L.

Overview

Appearance
Carduus pycnocephalus is an annual or sometimes biennial plant. It can grow from 1-4 ft. (0.3-1.2 m) tall.
Foliage
The stems have spiny wings. Leaves deeply cut into 2 to 5 pairs of lobes, have white spots and undersurface slightly woolly.
Flowers
The flowers range from purplish to pinkish, are borne in cylindrical heads either solitary or in clusters of more than 5. The bracts hairy. It blooms from May to June.
Fruit
Fruits from outer part of flower head are gray in color and inner portion are yellowish to tan.
Ecological Threat
Carduus pycnocephalus is native to southern Europe. It infests roadsides and waste areas, and has become a major problem on hill pasture land in Douglas County, Oregon. Once established, it spreads rapidly and forms dense stands which displace more desirable vegetation and exclude livestock.

General Description:

Carduus pycnocephalus, a member of the Thistle tribe of the Composite family, is an erect winter annual herb 3-18 dm tall.

Diagnostic Characteristics:

Carduus pycnocephalus can be distinguished from other thistle species by its relatively small and few terminal flowerheads and narrow phyllaries with copious tiny, firm, forward-pointing hairs, especially on the midrib (Hitchcock and Cronquist 1973).

Resources

Selected Images


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Italian plumeless thistle
Carduus pycnocephalus
Flower(s)
Eric Coombs
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5454487

Italian plumeless thistle
Carduus pycnocephalus
Plant(s)
Eric Coombs
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0024029

Italian plumeless thistle
Carduus pycnocephalus
Plant(s)
Eric Coombs
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Italian plumeless thistle
Carduus pycnocephalus
Foliage
Mary Ellen (Mel) Harte
5392003
5392003

Italian plumeless thistle
Carduus pycnocephalus
Flower(s)
John M. Randall
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5392005

Italian plumeless thistle
Carduus pycnocephalus
Seed(s)
John M. Randall
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5400988

Italian plumeless thistle
Carduus pycnocephalus
Plant(s)
Mary Ellen (Mel) Harte
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Italian plumeless thistle
Carduus pycnocephalus
Flower(s)
Mary Ellen (Mel) Harte
5400992
5400992

Italian plumeless thistle
Carduus pycnocephalus
Flower(s)
Mary Ellen (Mel) Harte
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5436212

Italian plumeless thistle
Carduus pycnocephalus
Flower(s)
Eric Coombs
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5454485

Italian plumeless thistle
Carduus pycnocephalus
Flower(s)
Eric Coombs
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0024030

Italian plumeless thistle
Carduus pycnocephalus
Infestation
Eric Coombs

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Carduus

Other System Links

Plants: CAPY2
Bayer: CRUPY
GRIN: 316603
ITIS: 35788
NPDN Pest: PBFAQBD

Synonyms and Other Names

Other Common Names:
compact-headed thistle, Italian thistle

Categories

Category: Forbs/Herbs