Paspalum distichum L.
Water Couch

Syst.Nat. Ed.10,2:855 (1759)
Conservation Code
Not threatened
Naturalised Status
Alien to Western Australia
Name Status

Tufted perennial, grass-like or herb, 0.05-0.5 m high. Fl. green/green-purple, Dec or Jan to Apr. Moist habitats, often saline.

Grazyna Paczkowska, Descriptive Catalogue, 1 December 1993


IBRA Regions
Dampierland, Geraldton Sandplains, Jarrah Forest, Swan Coastal Plain, Victoria Bonaparte, Warren.
IBRA Subregions
Dandaragan Plateau, Geraldton Hills, Keep, Northern Jarrah Forest, Perth, Pindanland, Southern Jarrah Forest, Warren.
Local Government Areas (LGAs)
Albany, Armadale, Augusta Margaret River, Broome, Busselton, Capel, Donnybrook-Balingup, Gingin, Gosnells, Greater Geraldton, Harvey, Kalamunda, Melville, Murray, Northampton, Perth, Rockingham, Serpentine-Jarrahdale, South Perth, Stirling, Wyndham-East Kimberley.

Management Notes (for the Swan NRM Region)

Alternative Names. Mercer grass, knotgrass, seashore paspalum, salt jointgrass, turfgrass.

General Biology. Growth form. Grass. Life form. Perennial, stoloniferous/rhizomatous. Reproduction. Stolon, rhizome, occasionally seed. Dispersal. Water. Photosynthetic Pathway. C4. Toxicity. Toxic to stock due to parasitic ergot fungus. Seedbank persistence. Possibly 2 years. Fire response. Resprouts from rhizomes.

Notes. Occurs in warm regions throughout the world, being most abundant in humid areas. Found on edges of wetlands, ponds and wet roadside drains. Has slow decomposition rates that can form permanent litter layers in wetlands. Eutrophication and disturbance exacerbates spread. Regeneration occurs mostly from rhizomes, although ecotypes have been known to reproduce readily from seed. Highest germination rates occur at temperatures between 28 and 35 degrees celsius. Seed has high viability. Alternating temperature and mositure breaks seed dormancy and results in high germination rates.

Additional information. History of use/introduction. Forage, rehabilitation of disturbed and contaminated sites, erosion control. Similar exotic species. Paspalum vaginatum.

Suggested method of management and control. Spray with 1% glyphosate 2-3 times over single growing season. Following any fire event is an optimal time to undertake control. 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

Calendar Type Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Comments
Dormant           Y Y Y Y        
Active Growth Y Y Y Y O         Y Y Y  
Germination                 U U U U  
Flowering Y Y Y Y               Y  
Fruiting Y Y                      
Herbicide Treatment Y Y Y Y O           Y Y  

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



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