Cobweb thistle is a tall, stout, leafy biennial
growing from 2' to 5' tall. The leaves are alternate, narrow-lanceolate,
wavy-margined, pinnately-lobed and spinose, and up to 12" long.
They are densely gray or whitish tomentose, especially beneath, and
the upper leaves are reduced in size, sessile, and ± clasping
or short-decurrent. The flowering heads are discoid, solitary on long
leafy stems that are somewhat thicker than those of California thistle.
The involucres are large, globose, to 2" in diameter, and densely
cobwebby. The phyllaries are acicular, spreading to ascending, and interconnected
by a webbing of fine, whitish tomentum. There are disk flowers only,
purplish-red with corollas to 1-1/4". The fruit is a brownish achene
about 1/4" long. Cobweb thistle inhabits sandy to grassy or brushy
locations in coastal strand, coastal sage scrub and chaparral, mostly
at fairly low elevations, from cismontane southern California to central
California, and blooms from April to July.
Click here for Latin name derivations: 1) Cirsium
Pronunciation: SIR-see-um ok-si-den-TAY-lee.
Click here for Botanical