Juncus acutus L.
Spiny Rush

Management Notes (for the Swan NRM Region)

Alternative Names. Spiny Rush, Cultivation Rush.

General Biology. Growth form. Sedge. Life form. Perennial. Reproduction. Primarily by seed, also crown fragments. Dispersal. Water, mud, soil movement, machinery, inappropriate or inadvertant plantings. Seedbank persistence. Seeds remain viable in laboratory conditions for 4 years, thought to be much shorter in the field. Fire response. Rhizomes are able to resprout after fire..

Notes. Naturalised in other Australian states and New Zealand. Establishes in disturbed natural ecosystems such as riparian vegetation and wetland areas. Once established, completely covers an area and eliminates all other vegetation, makes areas impenetrable to stock and humans because of the sharp spines, can restrict flow of water causing flooding, provide harbour for introduced fauna, particularly rabbits. Has allelopathic anti-aglae compounds. Tolerant of water logging (occurs along waterways), moderate salinity and drought. Long lived. Wind pollinated. Able to flower and set seed from two years of age onwards. Prefers light sands to loam although can also grow in heavy clay soil. Is a polymorphic species with numerous varieties described. Seed has high germination rates in light , however no germination occurs in the dark. Has 100% germination in freshwater, however this decreases with higher salinity, although ungerminated seeds are not damaged by salt or periods emersed in salt water. Known to hybridise with the native Juncus kraussii, which has marginally greater salinity tolerance. Has the potential to displace J. kraussii, particularly in areas that receive regular freshwater input. Similarly, periods of heavy rainfall, which reduce soil salinity, may help colonisation of new areas.

Additional information. Origin. Europe, Mediterranean, south-west Asia, southern and northern Africa, northern and southern America. History of use/introduction. It is unknown how Spiny Rush arrived in Australia. The earliest herbarium specimens were collected in the Sydney area.. Similar native species. Juncus kraussii, J. pallidus.

Suggested method of management and control. controlling infestations early and preventing further spread is the most effective form of management. Management programs using mechanical controls, chemicals, cultivation, altering salinity and drainage, and pasture management measures have been proposed. Spiny Rush may be dug out effectively, as the plant is shallow-rooted. The roots need to be severed and the top growth may also be burnt. The plant likes damp situations so improving drainage may help to reduce populations, but this would not be a suitable control measure where it is a weed in natural habitats such as wetlands. Chemical control is often impractical because of the difficulty of application to dense patches; therefore, mechanical removal of the existing growth, although costly, is often the most practical starting point in a control program, Read the manufacturers' labels and material safety data sheets before using herbicides. For further information consult the Australian Pesticides and Veterinary Medicines Authority to determine the status of permits for your situation or state.

Management Calendar

Legend: Y = Yes, regularly, O = Occasionally, U = Uncertain, referred by others but not confirmed.

 

References

• Brown, K. & Brooks, K. (2002) Bushland Weeds: A Practical Guide to their Management. Environmental Weeds Action Network, Greenwood.
• DellaGreca, M., Fiorentino, A., Monaco, P., Previtera, L. & Zarrellia, A. (2002) A new dimeric 9,10-dihydrophenanthrenoid from the rhizome of Juncus acutus. Tetrahedron Letters, 43 (14): 2573-2575.
• Department of Environment and Conservation (2006) Managing Sharp Rush. In (ed. Longman, V.). URL: https://www.dpaw.wa.gov.au/images/documents/conservation-management/off-road-conservation/urban-nature/workshops/proceedings_of_the_managing_sharp_rush_juncus_acutus_works.pdf Proceeedings of a workshop held at Wollaston College Conference Centre, Mt Claremont, Perth, Western Australia, 4 August 2006.
• Department of Primary Industries (2009) Invasiveness and Impact Assessment: Spiny Rush (Juncus acutus) (Nox). State of Victoria URL: http://www.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/weeds_perennial_spiny_rush - Accessed March 2010.
• Greenwood, M.E. & MacFarlane, G.E. (2006) Effects of salinity and temperature on the germination of Phragmites australis, Juncus kraussii and Juncus acutus: Implications for estuarine restoration activities. Wetlands, 26 (3).
• Greenwood, M.E. & MacFarlane, G.R. (2008) Effects of salinity on competitive interactions between two Juncus species. Aquatic Botany, 90: 23-29.
• Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. & Cousens, R.D. (2007) Western Weeds. A guide to the weeds of Western Australia. 2nd Edition. The Plant Protection Society of Western Australia, Victoria Park.
• Jones, V. & Richards, P.W. (1954) Juncus acutus L. Journal of Ecology, 42 (2): 639-650.
• Martínez-Sáncheza, J.J., Conesaa, E., Vicentea, M.J., Jiméneza, A. & Francoa, J.A. (2006) Germination responses of Juncus acutus (Juncaceae) and Schoenus nigricans (Cyperaceae) to light and temperature. Journal of Arid Environments, 66 (1): 187-191.
• Pacific Island Ecosystems at Risk (2008) Plant threats to Pacific ecosystems. URL: http://www.hear.org/pier/scinames.htm - Accessed January 2010.
• Parsons, W.T. & Cuthbertson, E.G. (2001) Noxious weeds of Australia. 2nd Edition. CSIRO Publishing, Collingwood.
• Paul, S. & Young, R. (2006) Experimental control of exotic spiny rush, Juncus acutus from Sydney Olympic Park, 1: Juncus mortality and re-growth. Wetlands (Australia), 23 (2): 1-13.
• Plants for a future (Undated) Juncus acutus - L. Sharp Rush. URL: http://www.pfaf.org/database/plants.php?Juncus+acutus - Accessed March 2010.
• Urban Nature (2006) Managing weeds in bushland: Sharp Rush (brochure). Environmental Weeds Action Network, Greenwood, Western Australia.
• USDA, ARS, National Genetic Resources Program (2009) Germplasm Resources Information Network - (GRIN). National Germplasm Resources Laboratory, Beltsville, Maryland. URL: https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx - Accessed October 2009.
• Vicente, M.J., Conesa, E., Alvarez-Rogel, J., Franco, J.A. & Martinez-Sanchez, J.J. (2009) Relationships between salt type and seed germination in three plant species growing in salt marsh soils of semi-arid Mediterranean environments. Arid Land Research and Management, 23 (2): 103-114.