Title: Xanthium spinosum L.

Scientific Name:

Xanthium spinosum L.

Common Names:

Bathurst burr, prickly burrweed



Sour & more images (via ALA)

Habitat: Exposed, moderately warm situations in temperate regions on high fertility disturbed soils, and is often associated with sheep camps, watercourses, dam banks and floodplains (Parsons and Cuthbertson, 1992). It is a serious competitor with such crops as cotton, maize, peas, potatoes, soybeans, sorghum and grapes (Parsons and Cuthbertson, 1992). Bathurst Burr invades lowland grassland and grassy woodland, riparian vegetation, freshwater wetland, and rock outcrop vegetation (Carr et al., 1992).

Distribution:

  
Present Distribution - Australia (source: ALA)   Present Distribution - USA (source: USDA)




Invasiveness Assessment

ESTABLISHMENT


1. Germination requirements? "Several germination's occur after late spring and summer rains or after irrigation". "In Australia, some seeds germinate out of season". (Parsons and Cuthbertson, 1992, p.319)

2. Establishment requirements? "Bathurst burr grows best in open, unshaded areas".. (Hocking & Liddle, 1995 p.246).

3. How much disturbance is required? Invades minor disturbed ecosystems, (e.g. lowland grassland and grassy woodland and rock outcrop vegetation). (Carr et al., 1992).

GROWTH / COMPETITIVE


4. Life form? Erect annual herb. Others category. (Parsons and Cuthbertson, 1992, p.318)

5. Allelopathic properties? None reported.

6. Tolerates herb pressure? "In some areas stock seem to relish Bathurst burr seedlings...more mature Bathurst burr plants are not palatable to stock" (Hocking & Liddle, 1995 p.246).

7. Normal growth rate?"Competes strongly with many summer crops". "Capable of forming extensive dominant stands under suitable conditions" (Parsons and Cuthbertson, 1992; Hocking and Liddle, 1995 p. 277).

8. Stress tolerance to frost, drought, w/logg, sal. etc? "It grows in drier conditions than Noogoora burr, but succumbs to water logging". Tolerates drought and frost (occurring in areas of Australia that experience both). However assumed to tolerate some water logging as occurs in seasonal fresh water wetlands. (Carr et al., 1992). Also likely to tolerate some salinity as the closely related Noogoora burr is moderate to quite high. (Hocking and Liddle, 1995 p. 262; Parsons and Cuthbertson, 1992 p. 318)

REPRODUCTION


9. Reproductive system? "Reproducing by seed". Male and female flowers on same plant. (Hocking and Liddle, 1995 p. 246; Parsons and Cuthbertson, 1992 p. 318)

10. Number of propagules produced? "Two seeds are produced in each burr". If 100 burrs per plant = 200 seeds per plant. "About 150 burrs are produced per plant". (Parsons and Cuthbertson, 1992 p. 321; Hocking and Liddle, 1995 p. 266)

11. Propagule longevity? "Some seed remains dormant in the soil for at least three years" (Parsons and Cuthbertson, 1992 p. 321) .

12. Reproductive period? Annual (Parsons and Cuthbertson, 1992 p. 318)

13. Time to reproductive maturity? Annual (Parsons and Cuthbertson, 1992 p. 318)

DISPERSAL


14. Number of mechanisms? Refer to ‘dispersal' -- animals, clothing and contaminated seeds (Parsons and Cuthbertson, 1992 pp. 319 & 321).

15. How far do they disperse? "Well adapted for dispersal because the hooked spines on the burrs cling firmly to the wool or fur of animals..." (Parsons and Cuthbertson, 1992 p. 319).


Impact Assessment

RECREATION


1. Restrict human access? Erect annual herb usually to about 1 metre high. Thick burr patches in pastures eliminate almost all other species, and may be so dense (up to 30 plants per square metre) that sheep are denied access to watering points." Similarly, because of the prickly nature of the plant, patches would restrict human access.(Parsons and Cuthbertson, 2001)

2. Reduce tourism? "In Victoria ...it exists on flood-prone areas along the [Murray River] and its tributaries. Xanthium spp. is spread widely along waterways." Dense patches would affect some recreational activities such as boating or fishing in these situations (Parsons and Cuthbertson, 2001).

3. Injurious to people? The fruit is a "woody ellipsoid burr 1.2 to 2.5 cm long." "The seed and seedlings are poisonous to animals...both species cause contact dermatitis in humans and the pollen may cause hay fever." (Parsons and Cuthbertson, 2001).

4. Damage to cultural sites? Dense patches would create a negative visual impact and seriously affect the aesthetics of an area.

ABIOTIC


5. Impact flow? Terrestrial species. (Parsons and Cuthbertson, 2001)

6. Impact water quality? Terrestrial species. (Parsons and Cuthbertson, 2001)

7. Increase soil erosion? A competitive annual, "thick burr patches in pastures eliminate almost all other species." Potential to leave areas of soil exposed to erosion. "In Australia, it thrives on the banks of rivers and creeks." In these situations there may be off-site implications associated with soil erosion (Parsons and Cuthbertson, 2001; Groves et al., 1995)

8. Reduce biomass? "...these plants [are] strong competitors in both pasture and summer crops." Direct replacement of biomass by invader (Parsons and Cuthbertson, 2001).

9. Change fire regime? Plants die in autumn, but remain standing. Dense patches may increase the intensity of fire risk (Parsons and Cuthbertson, 2001).

COMMUNITY HABITAT


10(a) Impact on composition of high value EVC? EVC=Creekline grassy woodland (E); CMA=North Central; Bioreg=Victorian Riverina; VH CLIMATE potential. It occurs along flood-prone areas of the Murray River and its tributaries. "Thick burr patches in pasture eliminate almost all other species." Prefers unshaded situations. Major impact on grasses/forbs (Parsons and Cuthbertson, 2001)

10(b) Impact on medium value EVC? EVC=Riverine grassy woodland (D); CMA=Goulburn Broken; Bioreg=Murray Fans; VH CLIMATE potential. Impact as in 10(a) above (Parsons and Cuthbertson, 2001).

10(c) Impact on low value EVC? EVC=Riparian forest (LC); CMA=West Gippsland; Bioreg=Highlands - Southern Fall; L CLIMATE potential. Prefers unshaded situations. Likely CLIMATE potential and forest situation would limit impact.

11. Impact on structure? "Noogoora burr can form very dense stands which are completely dominant and cover entire paddocks. Some forms prefer open communities and die out if shaded or crowded." Major impact on lower stratum (Groves et al., 1995).

12. Effect on threatened flora?

FAUNA


13. Effect on threatened fauna?

14. Effect on non-threatened fauna? In natural environments it is most likely to establish dense infestations in disturbed areas. It also tends to colonise in medium to large populations. In those situations, the presence of the weed would have a significant impact on the habitat of non-threatened fauna. Spiny nature of plant would deter grazing.. (Carr et al., 1992; Muyt, 2001; Parsons and Cuthbertson, 2001)

15. Benefits fauna? "Small birds feed on the seeds." Bird species not mentioned. Limited food source (Parsons and Cuthbertson, 2001).

16. Injurious to fauna? The plant has spines for most of the year. Potential for injury. (Parsons and Cuthbertson, 2001)

PEST ANIMAL


17. Food source to pests? Not known as a food source to pests. "The seeds and seedlings of both species are poisonous." (Parsons and Cuthbertson, 2001)

18. Provides harbor? Not known to provide harbor.

AGRICULTURE


19. Impact yield? "These plants [are] strong competitors both in pasture and summer crops such as maize, cotton and soybeans." Its presence in pasture seriously reduces carrying capacity. (Parsons and Cuthbertson, 2001)

20. Impact quality? Burrs contaminate wool reducing its value. "In 1978-79, between 7% and 8% of the wool sold in eastern Australia was contaminated with Noogoora burr." (Parsons and Cuthbertson, 2001)

21. Affect land values? The plant can be effectively controlled, but management programs can extend for more than six years to ensure the seed bank is exhausted. The cost of implementing such a program, plus the potential loss of income from reduced yields and quality, would likely have a negative impact on land value.

22. Change land use? With an appropriate control program, land use would not need to change significantly. "Neither species is particularly important to cattle producers." If the weed is left untreated, changing from sheep to cattle may be required. (Parsons and Cuthbertson, 2001)

23. Increase harvest costs? The burrs "...damage carding machines." The cost of processing contaminated wool increases. "...travelling stock must be inspected and any burrs removed." (Parsons and Cuthbertson, 2001)

24. Disease host/vector? "In North America, Noogoora burr is a host of two Sclerotinia pathogens which cause important diseases in soybeans. It is not known if it plays a similar role in Australia." Potential host a threat to agriculture. (Parsons and Cuthbertson, 2001)




Feedback

Do you have additional information about this plant that will improve the quality of the assessment? If so, we would value your contribution.


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:
bathurst burr_plant.jpg
bathurst_burr_present.jpg
bathurst_burr_potential.jpg
q=lsid_%22urn_lsid_biodiversity.org.au_apni.taxon_129387%22%20AND%20geospatial_kosher_true
XASP2.png
JPGurweed via ala.JPG
Related Articles
referenced by (3)
wra1033: Common Name - S (via spiny cocklebur)wra1029: Common Name - P (via prickly burrweed)wra825: Common Name - B (via Bathurst burr)
Article: wra525 (permalink)
Categories: :wra:x, :wra:inv1, :wra:invh, :wra:inv2, :wra:invml, :wra:inv3, :wra:invmh, :wra:inv4, :wra:invl, :wra:inv5, :wra:inv6, :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:imph, :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:imp16, :wra:imp17, :wra:imp18, :wra:imp19, :wra:imp20, :wra:imp21, :wra:imp22, :wra:imp23, :wra:imp24
Date: 29 July 2009; 1:01:12 PM AEST

Author Name: David Low
Author ID: adminDavid