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Taxon  Report  
Onopordum illyricum  L.
Illyrian cottonthistle,   Illyrian thistle
Onopordum illyricum is an annual or biennial herb that is not native to California.
There is a high risk of this plant becoming invasive in California according to Cal-IPC.
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
Observation Search
(21 records)
redone or more occurrences
within a 7.5-minute quadrangle
DJJJASONAFMM

Bloom Period
Genus: Onopordum
Family: Asteraceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Name Status:
Accepted by JEF + PLANTS

Information about  Onopordum illyricum from other sources

[Wikipedia] Europe native, Description, Noxious Weed: Onopordum illyricum is a species of thistle known by the common name Illyrian thistle,[1] or Illyrian cottonthistle.[2] It is native to southwestern Europe, but has been introduced into Australia and California, where it has become a noxious weed. The plant is a biennial herb producing an erect, branching, winged, spiny stem known to exceed two meters in maximum height. The spiny leaves may be up to 50 centimetres (20 in) long and are divided into deep toothed lobes. The inflorescence bears several large flower heads each up to 7 centimetres (3 in) wide. They are lined with spiny, woolly to cobwebby phyllaries and bear many narrow glandular purple flowers each about 3 centimetres (1.2 in) long. The fruit is a cylindrical achene 4 or 5 millimetres (0.16 or 0.20 in) long topped with a white pappus 1 centimetre (0.39 in) in length. (contributed by Mary Ann Machi)


Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2023. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 12/05/2023).