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AGAVE AND YUCCA | CACTI | WILDFLOWERS

Cirsium Occidentale, Cobwebby Thistle


Plants > Wildflowers > Asteraceae > Cirsium Occidentale
Cobwebby Thistle; Purple flower of cirsium occidentale (cobwebby thistle), in Harmony Headlands State Park
Purple flower of cirsium occidentale (cobwebby thistle), in Harmony Headlands State Park
Common names:
Cobwebby thistle, western thistle
Family:
Aster (Asteraceae)
Scientific name:
Cirsium occidentale
Main flower color:
Purple
Range:
Most of California, plus northwest Nevada and southwest Oregon
Height:
Up to 10 feet
Habitat:
Varied; coastal bluffs, sand dunes, roadsides, woodland
Leaves:
Grey-green, covered with white hairs, 12 inches or more in length; divided into toothed lobes
Season:
February to July
Pintrest
The common name of cirsium occidentale, cobwebby thistle, refers to the spherical cluster of long, sharply-spined phyllaries below the flowers, as these grow through a ball of a dense, cobweb-like material, which becomes more pronounced as the seeds form. The flower head is composed of hundreds of very narrow disc florets, each about 1.5 inches long, usually purple but sometimes red or whitish. Like the leaves, the thick, strong stems appear grey or even white due to a covering of hairs; the stem may reach a height of 10 feet or more, and branch quite profusely. Several varieties of this species are recognized, reflecting different characteristics of the corollas, involucres and growth habit.




Greyish-green leaves
Greyish-green leaves
Cobwebby Thistle
Flowerhead
Cobwebby involucre
Cobwebby involucre
Hairy stems
Hairy stems
Florets and phyllaries
Florets and phyllaries
Pink disc florets
Pink disc florets
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