Annual Beardgrass

Polypogon monspeliensis (L.) Desf.

Synonyms - Alopecurus monspeliensis

Family: Poaceae

Names:

Polypogon is from the Greek poly meaning many and pogon meaning a beard and refers to the soft bristly seed head.
Monspeliensis

Other Names

Annual Barbgrass.
Beardgrass .
Rabbit Foot Grass.

Summary:

A hairless, slender, tufted, winter-spring growing, annual grass with a long, soft, somewhat silvery, cylindrical seed head to 15 cm long.

Description:

Cotyledons:

One.

First Leaves:

Long and narrow.

Leaves:

Emerging leaf folded flat in the bud.
Blade - Long, narrow, parallel sided, 50-200 mm long x 2-8 mm wide, flat, roughened on the veins. tapered to a fine point. Midrib is not prominent. Tip pointed. Hairless.
Ligule - 3-15 mm long, membranous, pointed tip. Hairless or shortly hairy on the outer surface.

Auricles - None.
Sheath - Tubular. Hairless.

Stems:

Single or in small tufts, erect or spreading 40-900 mm tall, branching near the base. 3-6 nodes. Often rough beneath the flower head. Rarely bent at the nodes. Hairless

Flower head:

Dense, cylindrical, (or sometimes somewhat lobed) softly bristly, spike like panicle, 10-160 mm long x 6-35 mm diameter with long, protruding awns. Closely divided, short branches. Pale green to yellowish white covered in fine bristles that give it a silvery appearance in the sun. Main axis and branch axes hairless but branches finely roughened.
Spikelets fall complete and break off below the glumes with a very short remnant of stalk.

Flowers:

Spikelets - Flattened, 2-3 mm long. 1 bisexual floret on a very short stalk.
Glumes - Pale yellow green, narrowly oblong, 1 nerved, equal length, about 1-2.5 mm long, keeled, rough on the keel, slightly notched with the midrib continuing as a fine, roughened awn, 4-8 mm long or 2-3 times as long as the glume. Short hairs or hairless.
Lemma - 1-2.5 mm long, half as long as to almost equal to the glumes, shiny, smooth, translucent, flat topped, 4 toothed or 2 lobed, with a very short, delicate awn that falls off.
Palea - 2 lobed almost equal to the lemma
Stamens -
Anthers -

Seeds:

Small, 1 mm long, tan and darker towards the ends. Easily rubbed from the husks.

Roots:

Fibrous.

Key Characters:

Annual.
Membranous ligule, 3-15 mm long with a pointed tip.
No auricles.
Panicle cylindrical, dense.
Spikelets often more or less hidden by conspicuous straight awns, usually 1 fertile floret and no empty florets
Glumes with fine awns 2-3 times as long as base, 1 nerved, with 2 very short, blunt lobes.
Lemma 3-5 nerved, hyaline
Body of lemma hidden by the glumes.
Articulation below the glumes
Awns simple.
Adapted from John Black and John Moore.

Biology:

Life cycle:

Annual. Seeds germinate in autumn and it grows over winter and spring to set seed in late spring and persists well into summer.

Physiology:

Tolerant of salt.

Reproduction:

By seed.

Flowering times:

October to March in SA.
Spring in Western NSW.
November to May in WA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

Europe, Asia, Mediterranean, North Africa.
Naturalised in North and South America, New Zealand, Lord Howe Island

Distribution:

ACT, NSW, QLD, NT, SA, TAS, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Prefers moist situations, clay soils and slightly saline soils.

Plant Associations:

Prefers shaded places.

Significance:

Beneficial:

Fodder but only moderately palatable.

Detrimental:

Weed of irrigation crops, waterways, wetlands, grass lands, roadsides and disturbed areas.

Toxicity:

Not recorded as toxic

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Grazing or cultivation associated with cropping normally provides control.

Thresholds:

Eradication strategies:

Prevent seed set for 2-3 years. Spraying with 500 mL/ha glyphosate(450g/L) before flowering and repeating as necessary should provide reasonably selective control in bushland situations. Grass selective herbicides are not registered but are worth a trial.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Coastal Beardgrass (Polypogon maritimus) is smaller and has no awns on its lemmas.
Water Bent (Polypogon viridis = Agrostis viridis) is a stoloniferous perennial to 1000 mm tall.
Polypogon littoralis = Agropyron littoralis
Polypogon tenellus is a native species with purplish stems.

Plants of similar appearance:

Grasses.
Brome Grasses usually have a prominent midrib.
Barley Grass
Canary Grass
Phalaris

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P56. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P180.

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

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra).P50. Diagram.

Ciba Geigy (1981) Grass Weeds 2. CIBA GEIGY Ltd, Basle, Switzerland. P. Diagrams. P123. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P135-136. Photo.

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). P68.

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). #808.3.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P984.

Moerkerk, M.R. and Barnett A.G. (1998) More Crop Weeds. (R.G and F.J. Richardson, Melbourne). P40. Photos. Diagrams.

Paterson, J.G. (1977). Grasses in South Western Australia. (Western Australian Department of Agriculture Bulletin 4007). P83. Diagram.

Acknowledgments:

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