Soft Brome

Bromus hordeaceus L.

Synonyms - Bromus molliformis, Bromus mollis, Serrafalcus hordeaceus.

Family: Poaceae.

Names:

Bromus is the Greek word for oat.
Soft brome; soft refers to the silky touch of the seed head.

Other Names:

Barley Brome
Goose grass
Lop grass
Soft Chess

Summary:

A pale green, softly hairy leaved, annual grass with stems that are bent at the nodes and carry a compact seed head with soft awns.

Description:

Cotyledons:

One.

Leaves:

Leaves rolled in the shoot.
Blade - 100-300 mm long, 2-10 mm wide, flat, drooping. Finely pointed tip. Parallel sided. Parallel veins. Softly hairy on both the upper and lower surface. Usually light green.
Ligule - Membranous, more than 2 mm long. Tip obtuse and ragged.
Auricles - None.
Sheath - Tubular, hairy especially on the lower leaves.

Stems:

50-1000 mm tall. Tufted, erect, or ascending, slender to relatively stout, 2-5 nodes, bent at the nodes, round and hollow with solid nodes. Hairless near top, but usually furry below the panicle. Usually only has a few stems. Nodes are hairy.

Flower head:

Softly hairy. Usually a compact panicle (or spread out near base with elongated branches), erect, greyish green to purplish, egg shaped to oblong, 20-160 mm long with short branches, 2-10 mm long, with 1-7 spikelets that are initially loosely packed and erect and later more spreading. Breaks up at maturity.

Flowers:

Spikelets - Lance shaped to oblong, plump, on hairy stalks(pedicels), 3.5-6 mm wide x 10-22 mm long including the straight awns, narrowed towards the tip, bright or pale green, swollen, often hairy.
Florets - 5-14 per spikelet. Bright green with a pale margin when young
Glumes - Egg shaped, concave, tips acute or obtuse. First glume 3-7 nerved, 4-8 mm long. Second glume 5-7 nerved, 5-9 mm long. Both about the same size. Loosely hairy. Edges membranous.
Palea - 6-7.5 mm long, fine hairs towards the top.
Lemma - Lance to egg shaped, rounded on the back, edges translucent, 6-11 mm long. Narrowed toward the tip in side view. 7 or 9 nerved. Remains closed. Tip split into two membranous points. Tiny hairs or rough to touch especially toward the tip. Slender, erect awn, 1-10 mm long and is usually twice as long as the lemma and rough to touch and arises just below the split in the lemma.
Stamens -
Anthers -
Disarticulates above the glumes and between the florets.

Fruit:

Seeds:

Ellipsoid. 1 mm wide, 3 mm long. Yellow to brown. 1-10 mm Awn.

Roots:

Large fibrous root system.

Key Characters:

Biology:

Life cycle:

Annual or biennial grass. Germinates autumn/winter with the main flowering in spring but may continue flowering well into summer under favourable conditions.

Physiology:

Reproduction:

By seed.

Flowering times:

October to January in SA.
August to October with occasional flowers in November in WA.

Seed Biology and Germination:

Germination often stimulated by cultivation.

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Origin and History:

Europe and Western Asia.

Distribution:

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

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Prefers damp soils.

Plant Associations:

More abundant in shaded situations.

Significance:

Beneficial:

Fodder providing feed early in the season and matures later than many other annual pasture grasses.

Detrimental:

Weed of pastures, especially in higher rainfall areas and in damp areas, rotation crops, perennial crops, grass lands, gardens, wetlands and disturbed areas.

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

In pastures, graze heavily early in the season to reduce establishment and in spring to reduce seed set. Burn grassy stubble. Increase P, K and trace elements and reduce N applications. Plant competitive pasture species.

Thresholds:

Eradication strategies:

Preventing seed set for 1-2 years will provide control. Mowing and cultivation is usually effective whilst burning is more variable. 500 mL/ha of glyphosate(450g/L) applied when the grass is very young or flowering is fairly selective in native vegetation, cheap and effective. Both an early and late application may be needed. For hand spraying, use 10 mL glyphosate in 10 L water and spray until just wet.
Selective control amongst broad-leaved plants can usually be achieved with 100 mL/ha Verdict®520 or 800 mL/ha Fusilade®Forte or 500 mL/ha quizalofop(100g/L) plus 1% spray oil. For hand spraying, use 100 mL of spray oil plus 2 mL Verdict®520 or 16 mL Fusilade®Forte or 10 mL quizalofop(100g/L) per 10 L water.
In bushland areas replant shrub and tree species if necessary to provide shade and help stop re-infestation.
Avoid introducing new seed in contaminated produce.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Drooping Brome (Bromus tectorum) is mainly in Victoria and NSW and not recorded in WA.
Great Brome (Bromus diandrus var. diandrus and Bromus diandrus var. rigidus)
Madrid Brome (Bromus madritensis) tends to occur in drier areas.
Mediterranean Brome (Bromus lanceolatus) is not naturalised in WA and occurs mainly in Victoria and SA.
Prairie grass (Bromus catharticus)
Red Brome (Bromus rubens) tends to occur in drier areas.
Sand Brome (Bromus arenarius) is a native species.
Soft Brome (Bromus hordeaceus = Bromus mollis = Bromus molliformis)
Weedy Brome (Bromus alopecuros) Occasionally found in wheatbelt areas.

Plants of similar appearance:

B. molliformis is also called Soft Brome and is very similar but has hairless stems, the lemmas that are narrower, slightly smaller, less egg shaped and in side view they gradually (rather than abruptly) taper to the tip. The awn is sometimes twisted and spreading. The upper leaves tend to be less hairy. In 2009 it was declared to be the same species as Bromus hordeaceus.
Annual ryegrass, Barley grass, Brome grass, Darnel, Fountain grass, Guildford grass, Quaking grass, Sand fescue, Silver grass, Volunteer cereals, Wild oats, Toad rush, Winter grass.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P40.

Black, J.M. (1978). Flora of South Australia. (Government Printer, Adelaide, South Australia). P138. Diagram.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P30. Diagram.

Ciba Geigy (1981) Grass Weeds 2. CIBA GEIGY Ltd, Basle, Switzerland. P37. Diagrams.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P69.

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). #200.4.

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).P945.

Paterson, J.G. (1977). Grasses in South Western Australia. (Western Australian Department of Agriculture Bulletin 4007). P32.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P22. Diagrams. Photos.

Acknowledgments:

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