Parramatta Grass

Sporobolus indicus (L.) R.Br.

Synonyms - There are at least 3 varieties.
Parramatta Grass includes the following 2 species.
Sporobolus indicus var. capensis = Sporobolus indicus var. africanus = Sporobolus africanus = Sporobolus capensis = Sporobolus berteroanus = Sporobolus poiretti = Sporobolus elongatus = Agrostis africanus = Agrostis capensis
Sporobolus indicus var. major = Sporobolus indicus var. fertilis
Tussocky Sporobolus includes the following species.
Sporobolus diander = Sporobolus indicus var. flaccidus = Sporobolus diandrus

Family: Poaceae

Names:

Other Names

Rat's Tail Grass.
Smutgrass

Summary:

Perennial or biennial, tufted wiry grass that is strongly rooted in the soil and has long, thin, cylindrical seed heads.

Description:

Cotyledons:

One.

First Leaves:

Leaves:

Mainly basal. Emerging leaf rolled in the bud.
Blade - Narrow and tapering to a fine point, 60-300 mm long x 1.5-6 mm wide. Blue-green, rolled or flat. Hairless
Ligule - Short fringe of hairs, 0.2-0.5 mm long.
Auricles - Tuft of hairs.
Sheath - Hairless. Split to the base on older sheaths and rolled or overlapping on younger ones.

Collar - Lighter colour and often yellow or brown.
Stem leaves - Few. Hairless

Stems:

Flower stem - Erect, slender, 150-1000 mm tall, solid and pithy. Round in cross section near the top and grooved on one side near the base. Hairless.

Flower head:

Spike like panicle, dark green, sometimes slightly interrupted near the base. 60-400 mm long, 4-7 mm thick. Made up of many ascending branches, each 10-50 mm long. Hairless. Rachilla breaks above the glumes.

Flowers:

Spikelets - 1 flowered, small, 1.5-2.6 mm long, green to purplish with yellow anthers, awnless, stalked, hairless. Breaks above the glumes
Florets - 1, bisexual
Glumes - 2, membranous, shiny. Unequal, persistent, shorter than the floret, 1 vein. 1st glume is 0.5-0.8 mm long, oblong to elliptic with a flattish tip. 2nd glume is 1.5 mm long, egg shaped with a pointed tip and 1 vein.
Palea - Readily splits between the 2 veins, channelled. Slightly shorter than the lemma. Tip is flattish to slightly notched.
Lemma - >2 mm long, narrowly egg shaped to oblong, almost pointed with 1 vein. ~2 mm long, membranous. As long as or longer than the glumes. Awnless.
Stamens - 2 or 3.
Anthers -

Fruit:

Falls with palea, lemma and seed intact. Glumes left attached to the stem.

Seeds:

Free. Red-brown. Oval to tear shaped, 1.5 mm by 1 mm. Surface smooth to slightly frosty, grooved and hairless.

Roots:

Fibrous. White to yellow.

Key Characters:

Inflorescence not enclosed by the sheath
Panicle dense, spike like, dark green.
Spikelets 2.5 mm long, stalked, with 1 bisexual flower.
2nd (upper) glume shorter than lemma
Adapted from John Black, T.D. Macfarlane.

Biology:

Life cycle:

Perennial or biennial.

Physiology:

Reproduction:

By seed.

Flowering times:

November to June in SA.
September to November and March to June in WA.

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

Sporobolus indicus var. capensis - Africa and Lord Howe Island.
Sporobolus indicus var. major - Asia and the Pacific.

Distribution:

Sporobolus indicus var. capensis - ACT, NSW, QLD, NT, SA, TAS, VIC, WA.
Sporobolus indicus var. major - ACT, NSW, QLD, SA, TAS, VIC.
Higher rainfall areas in WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate to tropical.
High rainfall areas.

Soil:

Common in the coastal belt.

Plant Associations:

Significance:

Beneficial:

Fodder,
Sporobolus indicus var. capensis accumulates aluminium and is a high protein fodder when green but somewhat unpalatable, especially as it ages.
Sporobolus indicus var. major has its grain used for food and it stalks for brooms and hats.

Detrimental:

Weed of disturbed areas, lawns, roadsides.

Toxicity:

Not recorded as toxic.

Legislation:

Sporobolus indicus var. major is a noxious weed in NSW.

Management and Control:

Fertilising the land and introducing competitive pasture species usually results in Parramatta grass falling to very low levels in the sward.
Mowing is ineffective.

Thresholds:

It is not usually a problem in cropping situations.

Eradication strategies:

Control established plants by cultivation or herbicides then prevent seed set for 2-3 years.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Parramatta Grass (Sporobolus indicus var. capensis, Sporobolus indicus var. major)
Rat's Tail Couch (Sporobolus mitchellii)
Sand Couch (Sporobolus virginicus)
Tussocky Sporobolus (Sporobolus diander)
Western Rat's Tail Grass (Sporobolus creber)
Sporobolus africanus
Sporobolus coromandelianus
Sporobolus pyramidalis

Plants of similar appearance:

Western Rat's Tail Grass (Sporobolus creber) looks similar but has an interrupted seed head.
Sand Couch (Sporobolus virginicus) has grey seed heads rather than dark green and the glumes are equal in length.
Rat's Tail Couch (Sporobolus mitchellii) has light green seed heads and the glumes are equal in length.
African Lovegrass (Eragrostis curvula) often grows in association and looks similar until the seed head opens and spreads.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne).

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P208.

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Ciba Geigy (1981) Grass Weeds 2. CIBA GEIGY Ltd, Basle, Switzerland. P127. Diagrams.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P70. Photograph.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania).

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #954.6, #954.9.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P992.

Paterson, J.G. (1977). Grasses in South Western Australia. (Western Australian Department of Agriculture Bulletin 4007). P93. Diagrams.

Parsons, W.T. and Cuthbertson, E.G. (1992) Noxious weeds of Australia. (Inkata Press, Melbourne).

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.