Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Cirsium occidentale var. compactum
Photo is of parent taxon

compact cobwebby thistle
Habit Plants compactly branched, forming low rounded mounds, 5–100 cm, densely gray-tomentose.
Leaf

faces gray-tomentose or adaxial ± glabrate.
Involucres

wider than long, 5–8 cm diam., densely arachnoid with fine trichomes connecting tips of adjacent phyllaries.
Corollas

dark rose-purple, 25–30 mm.
Phyllaries

imbricate to subequal, outer and mid apices ± spreading, straight, usually 1–2 cm × usually 1–2 mm.
Heads

borne singly or in ± tight clusters, short-pedunculate, closely subtended and often overtopped by basal and large cauline leaves.
2n

= 30.

Cirsium occidentale var. compactum
Phenology Flowering winter–summer (Feb–Jul).
Habitat Coastal sea bluffs, dunes in grassland and coastal scrub
Elevation 0–50 m (0–200 ft)
Distribution
from FNA
CA
[BONAP county map]
Discussion

Variety compactum is locally common along the immediate coast of northern San Luis Obispo County and formerly ranged as far north as San Francisco. Populations referable to this race occur on the California Channel Islands and on the mainland in Monterey County. Because of the very narrow ecologic zone occupied by these plants they are particularly vulnerable to habitat loss. Variety compactum is closely related to vars. occidentale and coulteri.

of conservation concern

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 19, p. 139.
Parent taxa Asteraceae > tribe Cardueae > Cirsium > Cirsium occidentale
Sibling taxa
C. occidentale var. californicum, C. occidentale var. candidissimum, C. occidentale var. coulteri, C. occidentale var. lucianum, C. occidentale var. occidentale, C. occidentale var. venustum
Name authority Hoover: Vasc. Pl. San Luis Obispo Co., 310. (1970)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America

The species comparison tool is brought to you by:
Northwest Wildflowers