Cirsium arvense (L.) Scop.

Title: Cirsium arvense (L.) Scop.

Scientific Name:

Cirsium arvense (L.) Scop.

Common Name:

Californian thistle, perennial thistle

More images (via ALA)

Habitat: Subhumid to humid cool-temperate regions where it occurs in open, moderately warm situations up to subalpine levels (Parsons and Cuthbertson 1992). It prefers the more nitrogenous, deep loam soils in areas receiving more than 700 mm of annual rainfall (Parsons and Cuthbertson 1992). Californian thistle is a weed of indigenous grasslands, pastures, cultivated crops, roadsides and neglected sites (Parsons and Cuthbertson 1992).

Distribution:

Original source via CABI

Invasiveness Assessment

ESTABLISHMENT

1. Germination requirements? Flowering occurs in December/January. New shoots produced in late winter and early spring. (P & C, 1992)

2. Establishment requirements? Can establish under moderate canopy – occurs in forests/woodlands. (FEIS)

3. How much disturbance is required? Establishes in minor disturbed natural ecosystems e.g. woodlands, forests, grasslands, natural communities. “It was not found in undisturbed areas”. (FEIS; Thunhurst & Swearingen)

GROWTH / COMPETITIVE

4. Life form? Geophyte. Buds on root produce new shoots in winter/spring. (P & C, 1992)

5. Allelopathic properties? Produces allelopathic compounds, having an inhibitory effect on the growth of other plants. (P & C, 1992)

6. Tolerates herb pressure? Stock avoid grazing in and around dense patches. “Unpalatable to livestock and wildlife”. (P & C, 1992; FEIS)

7. Normal growth rate? “Growth is prolific”. It is strongly competitive in pastures and crops. (P & C, 1992)

8. Stress tolerance to frost, drought, w/logg, sal. etc? Tolerance to drought (occurs in desert shrub), frost (occurs in alpine areas), fire, water logging (occurs in wet areas). (FEIS - P & C, 1992;
Thunhurst & Swearingen)

REPRODUCTION

9. Reproductive system? Reproducing by seed and from extensive creeping rhizome. (P & C, 1992)

10. Number of propagules produced? Between 5-6,000 seeds per plant under favourable conditions. (According to European studies). (P & C, 1992)

11. Propagule longevity? Small % remain viable in the soil for at least 21 years. (P & C, 1992)

12. Reproductive period? “The deep roots grow horizontally and send up shoots along their length, forming dense colonies”. (Callihan & Miller)

13. Time to reproductive maturity? Some plants flower in their first year but this is not common. (P & C, 1992)

DISPERSAL

14. Number of mechanisms? Wind, water, machinery, equipment. (P & C, 1992)

15. How far do they disperse? Studies show wind disperses seeds only tens of metres. “Seeds travelling in irrigation canals and rivers causes new infestations far from the seed source. The parachuting effect of the pappus allows wind to carry Canada Thistle seed several hundred yards before settling”. (FEIS). “Canada thistle produces an abundance of bristly-plumed seeds which are easily dispersed by the wind”. (Thunhurst & Swearingen 1999). (P & C, 1992)

Impact Assessment

RECREATION

1. Restrict human access? An erect perennial herb commonly 60 to 90 cm high. Growth is prolific and patches with 130 shoots per square metre are not uncommon, but not all shoots produce flower stems. The leaf margins bear spines. Densely infested areas would be an annoyance humans requiring access. (P & C, 2001)

2. Reduce tourism? In addition to agricultural situations, the plant occurs on neglected sites and roadsides. Recreational activities in these areas would be affected, with a major impact on aesthetics during growth and flowering. (P & C, 2001)

3. Injurious to people? Spines are present for most of the year. “The fine pappus bristles are claimed to irritate the skin and eyes of some people.” (P & C, 2001)

4. Damage to cultural sites? Its presence would create a moderate visual effect. The root system is extensive and aggressive, however, there is no evidence to suggest roots or growth habit would affect physical structures. It grows poorly in shaded conditions. (P & C, 2001; WSNWCB)

ABIOTIC

5. Impact flow? Terrestrial species. (P & C, 2001)

6. Impact water quality? Terrestrial species. (P & C, 2001)

7. Increase soil erosion? Aerial parts of the plant die off in late summer and with its strongly competitive nature it is likely to leave infested areas exposed to wind erosion. The extensive perennial root system provides soil stability against erosion by water. (P & C, 2001)

8. Reduce biomass? Occurs mostly in open situations such as pastures and neglected sites. Direct replacement of biomass or slightly increase. (P & C, 2001)

9. Change fire regime? In dense infestations, the dry matter left when the plant dies off in late summer may result in a slight increase in fire frequency risk. (P & C, 2001)

COMMUNITY HABITAT

10(a) Impact on composition of high value EVC? EVC= Plains grassy woodland (E); CMA=West Gippsland; Bioreg=Gipplsand Plain; VH CLIMATE potential. “[It] is a successful weed in grassland…[and] is strongly competitive in pasture.” However it does not, “…establish where there is existing ground cover.” Displace grasses/forbs in disturbed areas. (P & C, 2001)

10(b) Impact on medium value EVC? EVC=n/a; CMA=n/a; Bioreg=n/a. Does not appear likely to occur in any medium value EVCs in Victoria. (P & C, 2001)

10(c) Impact on low value EVC? EVC=Heathy woodland (LC); CMA=Wimmera; Bioreg=Glenelg Plain; VH CLIMATE potential. “[It] is a successful weed in grassland…[and] is strongly competitive in pasture.” However it does not, “…establish where there is existing ground cover.” Displace grasses/forbs in disturbed areas. (P & C, 2001)

11. Impact on structure? The plant has prolific growth, competes strongly for soil resources and produces allelopathic compounds inhibiting the growth of other plants. In non-agricultural areas it is generally confined to roadsides and neglected sites and its presence in these areas would dominate the floral structure. In the USA it is reported to occur in forest margins, however, it grows poorly in shaded areas and is unlikely to affect overstorey layers in these areas. (P & C, 2001; WSNWCB)

12. Effect on threatened flora? No documented effect.

FAUNA

13. Effect on threatened fauna? No documented effect.

14. Effect on non-threatened fauna? It has not occurred as a significant weed in natural ecosystems in Victoria (it is not recorded in Carr et al (1992)). In the United States it is recorded as occurring in natural communities, reducing plant and animal diversity. It is highly invasive and, as its prickly nature deters grazing, dense infestations would affect habitat. (Thunhorst & Swearingen, 1997)

15. Benefits fauna? No known benefits.

16. Injurious to fauna? If forced to eat the weed, young sheep can injure their mouths, possibly leading to infection. Potential for native fauna to suffer similarly. (P & C, 2001)

PEST ANIMAL

17. Food source to pests? Not known as a food source to pest animals. In Germany, rats are known to use plant parts for food. (P & C, 2001)

18. Provides harbor? Not known as a harbor for pests. May provide limited harbor for minor pest such as rodents.

AGRICULTURE

19. Impact yield? “It is strongly competitive in pastures (reducing forage) and crops such as potatoes, asparagus and peas. In the United States heavy infestations reduce yields of spring cereals by between 40% and 70%.” (P & C, 2001; WSNWCB)

20. Impact quality? Its dispersal throughout the world has been attributed to contaminated agricultural seeds. Thus its presence would affect the quality of seed harvests. It is also a problem in pea crops, “…the flower buds are similar in size, shape and texture to shelled peas and are difficult to grade out of the final product.” (P & C, 2001)

21. Affect land values? The plant is difficult to control particularly in cropping situations where cultivation can spread the weed and herbicides tolerated by crops have little or no effect. Its presence would affect the value of land. (P & C, 2001; Dept of Ag, WA)

22. Change land use? The presence of the weed in cropping situations may dictate a change to grazing until it is controlled.

23. Increase harvest costs? Apart from the problem in pea crops, C. arvense is not known to have an appreciable impact on harvesting costs. (P & C, 2001)

24. Disease host/vector? “It harbours insects that attack some commercial crops and it is an alternate host for certain plant pathogens.” (P & C, 2001)

Feedback

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Assessment ratings originally made by the Victorian Department of Primary Industries.

The entry of this assessment was made possible through the generous support of The Weed's Network.

Attachments:

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Calif vi ala.JPG
distribution_map (17).png

referenced by (1)

wra997: Common Name - C (via Californian thistle)

Article: wra1466 (permalink)
Categories: :wra:c, :wra:inv1, :wra:invmh, :wra:inv2, :wra:inv3, :wra:inv4, :wra:invml, :wra:inv5, :wra:inv6, :wra:invh, :wra:inv7, :wra:inv8, :wra:inv9, :wra:inv10, :wra:inv11, :wra:inv12, :wra:inv13, :wra:inv14, :wra:inv15, :wra:imp1, :wra:impmh, :wra:imp2, :wra:imp3, :wra:imp4, :wra:impml, :wra:imp5, :wra:impl, :wra:imp6, :wra:imp7, :wra:imp8, :wra:imp9, :wra:imp10a, :wra:imp10b, :wra:imp10c, :wra:imp11, :wra:imp12, :wra:impm, :wra:imp13, :wra:imp14, :wra:imp15, :wra:imph, :wra:imp16, :wra:imp17, :wra:imp18, :wra:imp19, :wra:imp20, :wra:imp21, :wra:imp22, :wra:imp23, :wra:imp24
Date: 5 October 2009; 10:49:08 AM AEDT

Author Name: Jessica Mackay
Author ID: mackayj