Taxon Report
Cirsium occidentale (Nutt.) Jeps. var. compactum Hoov.compact cobwebby thistle |
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Taxon Summary
Cirsium occidentale var. compactum, commonly known as compact cobwebby thistle, is a perennial herb in the Asteraceae that is found only in California. It occurs within Chaparral, Coastal dunes, Coastal prairie, and Coastal scrub, growing at elevations from 5 to 150 meters. Cirsium occidentale var. compactum is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.Classification
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Scientific Name: |
Cirsium occidentale (Nutt.) Jeps. var. compactum Hoov. |
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Common Name: |
compact cobwebby thistle |
| Family: | Asteraceae |
| Element Code: | PDAST2E1Z1 |
| USDA Plants Symbol: | CIOCC2 |
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Synonyms/Other Names: |
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Ecology and Life History
| Lifeform: | perennial herb |
| Blooming Period: Apr-Jun | Apr-Jun |
| Elevation: | 5-150 (15-490) |
| General Habitats: | Chaparral, Coastal dunes, Coastal prairie, Coastal scrub |
| Microhabitat: | |
| Microhabitat Details: |
Conservation Status
| CA Rare Plant Rank: | 1B.2 |
| Global Rank: | G3G4T2 |
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State Rank: |
S2 |
| State List: | None |
| Fed List: | None |
| Other Status: | BLM_S |
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CRPR Changes: |
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Occurrence Data from the CNDDB
| Total Occurrences: | 30 |
| Element Occurrence Ranks: | |
| Excellent (A) | 1 |
| Good (B) | 3 |
| Fair (C) | 3 |
| Poor (D) | 1 |
| None (X) | 1 |
| Unknown (U) | 21 |
| California Endemic: True | |
| California Counties and Islands: Name (Code) | |
| Los Angeles (LAX), Monterey (MNT)?, San Francisco (SFO)*, San Luis Obispo (SLO), San Mateo (SMT), Santa Barbara (SBA) | |
| Quads: Name (Quad Code) | |
| Big Sur (3612137), Cambria (3512151), Cayucos (3512048), Pfeiffer Point (3612127), Pico Creek (3512152), Piedras Blancas (3512163), Point Sal (3412086), Point Sur (3612138)?, San Francisco South (3712264)*, San Miguel Island East (3312083), San Miguel Island West (3312084), San Simeon (3512162), Santa Catalina East (3311833), Santa Rosa Island North (3312081), Santa Rosa Island South (3312071), Santa Rosa Island West (3312082) | |
Threat List Data from the CNDDB
| Threat List Total: | 5 | |
| EOs with Threat Listed: | Total EOs | % of EOs |
| 9 | 30 % | |
| Road/trail construction/maint. | 5 | 16% |
| Grazing | 4 | 13% |
| Non-native plant impacts | 3 | 10% |
| Erosion/runoff | 2 | 6% |
| Development | 1 | 3% |
Notes
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Known from fewer than twenty occurrences. Threatened by grazing and insect predation, and potentially by road construction and development. Some inland plants weakly separated from var. occidentale |
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Threats: |
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Taxonomy: |
Citation
California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 5 February 2025].