Italian Ryegrass

Lolium multiflorum Lam.

Synonyms - Lolium italicum, Lolium perenne var. multiflorum.

Family: - Poaceae.

Names:

Lolium is from the Greek word for craft, deceitful or treacherous because Darnel (L. temulentum) can be toxic and it was believed to be a changed form of wheat.

Multiflorum because it has many flowers in each spikelet.

Italian Ryegrass

Other names:

Concord Ryegrass

New Zealand Italian Ryegrass = Paroa Ryegrass

Paroa Ryegrass

Tama Ryegrass

Westerwolds Ryegrass

Summary:

A winter growing, hairless, shiny leaved, palatable annual or biennial pasture grass with up to 38 florets in each spikelet.

Description:

Cotyledons:

One

Leaves:

Rolled in the bud. In rolled when young. The basal leaves often dry before the seed head matures.

Blade - 60-220 mm long by 2-10 mm wide, many ribs. Shiny on the lower surface. Hairless.

Ligule - Membranous, rounded, flat topped or jagged, 4 mm long.

Auricles - Large, narrow, hairless.

Sheath - Hairless. Basal ones often purplish. Split to the base.

Stems:

700-1000 mm tall, tufted, erect or spreading.

Flower head:

Slender spike, 100-400 mm long, straight or slightly curved, zig zag at each flower cluster, 5-38 spikelets. Main axis mostly rough. Hairless. Often doesn't fully emerge from the top sheath.

Flowers:

Spikelets - 5-31 mm long (excluding awns), stalkless. Lying in concave section of stem. Spreading when in flower. Usually awned. 10-22 florets. Hairless.

Florets - All bisexual or 1 empty (especially in the end spikelet). Narrowly oval.

Glumes - Narrow egg shape. Back rounded. 5-14 mm long, shorter than floret. 3-7 ribs. Hairless. First glume is similar to the second and only present in the terminal spikelet. Second glume is 5-14 mm long, 3-7 nerved.

Palea - Similar to lemma. Keels with very small teeth.

Lemma - Narrow egg shape. Back rounded. 4-8 mm long. 3-5 nerved. Tip is slightly jagged or 2 lobed and translucent. Usually has a straight awn about the same length as the lemma or 3-15 mm long, attached just below the tip.

Stamens -

Anthers -

Breaks above the glumes and between the florets.

Fruit:

Awned.

Seeds:

Narrowly oval grain.

Roots:

Fibrous.

Key Characters:

Florets lance shaped, not swollen in fruit. Lemmas awned. Grain linear-oblong.

Biology:

Life cycle:

Biennial or annual. Flowers November to December and occasionally at other times.

Physiology:

Reproduction:

By seed.

Flowering times:

June to summer in SA.

November to December in Perth.

Flowers in spring in WA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Crosses with other ryegrass species. When crossed with perennial ryegrass it is larger and flowers earlier.

Varieties include Concord, Paroa, Tama, Westerwolds.

Allelopathy:

Population Dynamics and Dispersal:

Spread by intentional planting and seed.

Origin and History:

Europe. North Africa. Asia.

Distribution:

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

NSW, Qld, SA, Tas, Vic, WA.

Habitats:

Climate:

Temperate. Mediterranean.

Most varieties prefer high rainfall, long growing season areas.

Soil:

Prefers fertile soils.

Plant Associations:

Significance:

Beneficial:

Fodder.

Detrimental:

Weed of rotation crops, grass land and disturbed areas.

Toxicity:

May cause nitrite poisoning especially in calves.

Symptoms:

Nitrite poisoning.

Treatment:

Restrict grazing to 1 hour per day.

Legislation:

Management and Control:

Thresholds:

Eradication strategies:

Herbicide resistance:

Biological Control:

Related plants:

Annual Ryegrass (Lolium rigidum) has a glume about as long as the spikelet.

Darnel (Lolium temulentum)

Italian Ryegrass (Lolium multiflorum) has it leaves rolled in the bud rather than folded and has an awn on the lemma.

Perennial Ryegrass (Lolium perenne) has a glume about half the length of the spikelet.

Stiff Ryegrass (Lolium loliaceum)

Plants of similar appearance:

Barley grass, Brome grass, Fountain grass, Guildford grass, Quaking grass, Sand fescue, Silver grass, Volunteer cereals, Wild oats, Toad rush, Winter grass.

References:

Black, J.M. (1978). Flora of South Australia. (Government Printer, Adelaide, South Australia). P149.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P26.

Ciba Geigy (1981) Grass Weeds 2. CIBA GEIGY Ltd, Basle, Switzerland. P100. Diagrams.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P323-324.

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). P58.

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

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #757.2.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P967.

Paterson, J.G. (1977). Grasses in South Western Australia. (Western Australian Department of Agriculture Bulletin 4007). P60-61. Diagram.

Acknowledgments:

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