Plant Assessment Form

Cirsium vulgare

Synonyms: Carduus lanceolatus, Cirsium lanceolatum

Common Names: bull thistle

Evaluated on: 6/7/05

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org
Joseph DiTomaso
University of California-Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Joe DiTomaso
Alison Stanton
Joanna Clines
Cynthia Roye
Doug Johnson

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 3.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U
Impact?
Four-part score UBBU Total Score
B
1.2 ?Impact on plant community B. Moderate Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels B. Moderate Other Published Material
1.4 ?Impact on genetic integrity U. Unknown Reviewed Scientific Publication
2.1 ?Role of anthropogenic and natural disturbance in establishment A. Severe Reviewed Scientific Publication
Invasiveness?
Total Points
12 Total Score B
2.2 ?Local rate of spread with no management C. Stable Other Published Material
2.3 ?Recent trend in total area infested within state C. Stable Other Published Material
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal B. Moderate Reviewed Scientific Publication
2.6 ? Potential for natural long-distance dispersal C. Rare Reviewed Scientific Publication
2.7 ?Other regions invaded C. Already invaded Reviewed Scientific Publication
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Reviewed Scientific Publication
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
C. Low Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? U
Identify ecosystem processes impacted:

no information


Sources of information:

Question 1.2 Impact on plant community composition,
structure, and interactions?
B Reviewed Scientific Publication
Identify type of impact or alteration:

Dominates recently clearcut forests in the Sierra Nevadas. Growth of ponderosa pine was limited by bull thistle rosettes. Can form dense stands (1). Bull thistle also colonizes and maintains high population densities for up to six years in clearcuts in redwood and mixed evergreen forests in northwestern California (2).


Sources of information:

Question 1.3 Impact on higher trophic levels? B Other Published Material
Identify type of impact or alteration:

Displaces forage species used by native ungulates such as deer and elk (1).


Sources of information:

Question 1.4 Impact on genetic integrity? U Reviewed Scientific Publication

Hybridization with bull thistle has been suggested for endangered Cirsium hydrophyllum var. hydrophyllum in California. However, there is no evidence of this (1), chromosome numbers make it highly unlikely (Hickman, 1993), and the claim almost certainly a case of mis-identification (Dean Kelch, pers com to Daniel Gluesenkamp 2001). There are numerous native thistles in California, but no information on hybridization (2).


Sources of information:

1. Forcella F., Randall J.M. 1994. Biology of Bull Thistle, Cirsium vulgare (Savi) Tenore. Rev. Weed Sci. 6:29-50.
2. Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
C Other Published Material
Describe role of disturbance:

It is most troublesome in recently or repeatedly disturbed areas such as pastures, overgrazed rangelands, recently burned forests and forest clearcuts, and along roads, ditches, and fences. Even small-scale disturbances such as gopher mounds promote bull thistle establishment and survival. It can also colonize areas in relatively undisturbed grasslands, meadows, and forest openings.


Sources of information:

Question 2.2 Local rate of spread with no management? C Other Published Material
Describe rate of spread:

Already present in most of California, so probably not spreading much.


Sources of information:

USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.


Question 2.3 Recent trend in total area infested within state? C Other Published Material
Describe trend:

Already present in most of California, so probably not spreading much. Transient populations enter after disturbance, then disappear.


Sources of information:

USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Joe DiTomaso, UC Davis, pers. obs.


Question 2.4 Innate reproductive potential? A Reviewed Scientific Publication
Describe key reproductive characteristics:

Biennial. Reproduces only by seed. Flowers are bisexual and can be either self- or cross-pollinated. Plants in California had >60 infloresences, but inflorescences per plant ranged from 1 to 475. Under favorable conditions, bull thistle can produce about 200 seeds/inflorescence (1). Other studies found a mean of 4000 seeds per plant, with germination ranging from 60-90% (2). Less than 5% of plants cut at the soil surface resprouted. However, bull thistle can resprout if cut early in the season (1). Flowering may occur from early June until the first snowfall or hard frost; in California there is a pronounced peak in July and early August. Seeds ripen and are released from early July through October, occasionally later along the coast (3).


Sources of information:

Question 2.5 Potential for human-caused dispersal? B Reviewed Scientific Publication
Identify dispersal mechanisms:

Transported by vehicles and farm equipment. Most common method of transport is in contaminated hay (1).


Sources of information:

1. Mitich L.W. 1998. Intriguing World of Weeds, Bull Thistle, Cirsium vulgare. Weed Technology 12: 761-763.


Question 2.6 Potential for natural long-distance dispersal? C Reviewed Scientific Publication
Identify dispersal mechanisms:

Unlikely. Most seeds fall close to the parent plant. Only 10% are transported >32m.


Sources of information:

1. Forcella F., Randall J.M. 1994. Biology of Bull Thistle, Cirsium vulgare (Savi) Tenore. Rev. Weed Sci. 6:29-50.
John Randall, The Nature Conservancy, pers. obs.


Question 2.7 Other regions invaded? C Reviewed Scientific Publication
Identify other regions:

Native to Europe. Introduced in North America, Australia, Chile, and New Zealand. In other areas, occurs in grasslands, roadsides, coastal dunes, woodland clearings, rock outcroppings, and on banks of rivers and streams (1). The species occurs on every continent except Antarctic (2). Present in all US states (3). Scoring as C because widespread in California.


Sources of information:

1. Klinkhamer P.G.L., de Jong T.J. Biological Flora of the British Isles: (Carduus lanceolatus L., Cirsium lanceolatum (L.) Scop., non Hill) Journal of Ecology 81: 177-191. 1993.
2. .Forcella F., Randall J.M. 1994. Biology of Bull Thistle, Cirsium vulgare (Savi) Tenore. Rev. Weed Sci. 6:29-50.
3. USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Reviewed Scientific Publication

Present through most of California (1). Dominates recently clearcut forests in the Sierra Nevadas. Considered a serious pest in Yosemite National Park (2). In California, most common in coastal grasslands, along edges of fresh and brackish marshes, and in meadows and mesic forest openings in the mountains below 7,000 feet (2,120 m). By 1925 it had been reported in California from the San Francisco Bay Area, Central Valley, Klamath region, North Coast, and the northern Sierra Nevada (3).


Sources of information:

1. USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
2. Forcella F., Randall J.M. 1994. Biology of Bull Thistle, Cirsium vulgare (Savi) Tenore. Rev. Weed Sci. 6:29-50.
3. Randall, J. M. 2000. in Bossard, C. C. , J. M. Randall, and M. C. Hoshovsky. Invasive Plants of Californias Wildlands. University of California Press, Berkeley, CA. Also on-line: http://groups.ucanr.org/ceppc/Invasive_Plants_of_California's_Wildlands/


Question 3.2 Distribution/Peak frequency? C Observational
Describe distribution:

Sources of information:

Dan Gluesenkamp, Audubon Canyon Ranch, observational.
Peter Warner, California Dept. of Parks and Recreation, pers. obs.
Joanna Clines, US Forest Service, pers. obs.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Yes
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually Yes
Seeds remain viable in soil for three or more years Yes
Viable seed produced with both self-pollination and cross-pollination Yes
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 9
Total unknowns: 0
Total score: A?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrub
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralD, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieC, 5% - 20%
valley and foothill grasslandD, < 5%
Great Basin grassland
vernal pool
meadow and seepC, 5% - 20%
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swampC, 5% - 20%
Riparian and Bottomland habitatriparian forestD, < 5%
riparian woodlandD, < 5%
riparian scrub (incl.desert washes)D, < 5%
Woodlandcismontane woodlandD, < 5%
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forestC, 5% - 20%
closed cone coniferous forestD, < 5%
lower montane coniferous forestC, 5% - 20%
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): A
Distribution (highest score): C

Infested Jepson Regions

Click here for a map of Jepson regions

  • CA Floristic Province
  • Cascade Range
  • Central West
  • Desert Province
  • Mojave Desert
  • Sonoran Desert
  • Great Basin Province
  • Great Valley
  • Modoc Plateau
  • Northwest
  • Sierra Nevada
  • Sierra Nevada East
  • Southwest