Barley

Hordeum vulgare L.

Synonyms - Hordeum distichon, Hordeum hexastichon

Family: Poaceae.

Names:

Hordeum is the Latin name for Barley.
Vulgare is from the Latin vulgaris meaning common.
Barley.
2 rowed Barley - Hordeum vulgare var. distichon has 2 rows of seeds.
6 rowed Barley - Hordeum vulgare var. hexastichon has 6 rows of seeds.

Other names:

Cultivated Barley.

Summary:

Single to many stemmed grass with a cylindrical awned seed head and plump grain.

Description:

Cotyledons:

One

First leaves:

Grow singly, similar to later leaves.

Leaves:

Emerging leaf rolled in the bud.
Blade - Flat. Hairless or a few scattered hairs. Parallel sided. Clockwise twist.
Ligule - Short, membranous, translucent.
Auricles - Large, clasping and encircling the stem.
Sheath - Smooth. Upper most leaf sheath is swollen. Rolled and overlapping. Hairless or with a few scattered hairs.
Collar - Prominent and lighter than the leaves. Hairless or with a few scattered hairs.

Stems:

Up to 1500 mm, hollow except at the nodes. Arise from the base and unbranched. Hairless.

Flower head:

Spike, up to 150 mm long. Does not break up at maturity. Arranged in 2 rows of 3 spikelets.
2 rowed Barley (Hordeum vulgare var. distichon) has 2 rows of seeds with the outer 2 spikelets empty. The seed is in 2 distinct and opposite rows on the head giving the head a flattened appearance.
6 rowed Barley (Hordeum vulgare var. hexastichon) has 6 rows of seeds making the head almost cylindrical.

Flowers:

Spikelets - Persistent. Centre spikelet stalkless. Lateral spikelets on short stalks. In 2 rowed barley (var. distichon), lateral spikelets are empty. In 6 rowed barley (var. hexastichon) lateral spikelets are bisexual.
Florets - 1 in each spikelet.
Glumes - Persistent, hardened. Tip extended into a rough awn up to 100 mm long, or may be awnless.
Palea - Same length as lemma. 2 keeled. Deeply folded between keels.
Lemma - Bristle like awn of lemma of central spikelet at least 50 mm long. Hardened. Broadly rounded on back. 5 ribs. Attached to seed.
Stamens -
Anthers - White to pale yellow. Poke out of spikelet at maturity.

Fruit:

Grain. Oval, grooved, awned glumes firmly attached.

Seeds:

Pale yellow, oval grain, 4-8 mm long x 2-5 mm wide, with a brittle awn that is often broken off just above the grain. Husks are strongly attached to the grain.

Roots:

Fibrous. About 1000 mm deep, occasionally deeper.

Key Characters:

Spike does not break up at maturity. Awn of lemma of central spikelet is at least 50 mm long.

Biology:

Life cycle:

Annual. Flowers September to April. Germinates at any time of the year after rain, grows several leaves, then produces tillers or secondary stems from the base. Tillers elongate in spring (or autumn) conditions and produce a seed head with plump oval and awned grain.

Physiology:

Moderate tolerance of salinity. A 40% loss in production can be expected on soils with a soil conductivity of 15 mS/cm and a 10% loss at 9 mS/cm (558).

Reproduction:

By seed.

Flowering times:

April, May and September in SA.
Spring to Autumn in WA.
September to May in Perth.

Seed Biology and Germination:

Seed with husks had an after ripening period of 60 days and for de-husked seed it was 45 days (524).
No long term dormancy.

Vegetative Propagules:

None.

Hybrids:

Many commercial cultivars have been produced by hybridisation.

Allelopathy:

Stubble may be reduce the germination and growth of plants in the following season.

Population Dynamics and Dispersal:

Rarely persists for more than a season or two without the input of fresh seed from human sources such as planting or spillage from transporting vehicles.

Origin and History:

Europe. Asia.

Distribution:

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

Courtesy Australia's Virtual Herbarium.

Habitats:

Temperate regions.

Climate:

Temperate.

Soil:

Most soil types.

Plant Associations:

Significance:

Beneficial:

Major cereal crop grown for human and animal consumption and malt for brewing.

Detrimental:

Weed of other crops, occasional weed of roadsides and disturbed areas but generally not persistent.

Toxicity:

May cause grain poisoning.
May contain toxic amounts of nitrate, causing nitrate poisoning but no field cases have been reported.
Ergot infested seed is toxic.
Gibberella infested seed may be toxic but animals usually refuse to eat it.

Symptoms:

Depression then death.

Treatment:

Introduce animals slowly to grain and stubbles.

Legislation:

None.

Management and Control:

Grazing and cultivation provide high levels of control.

Thresholds:

In broadleaf crops, 5-10 plants/m2 are usually worth spraying.

Eradication strategies:

Prevent spillage from transporting vehicles.
Not required as it rarely survives for more than a few seasons.

Herbicide resistance:

None reported.

Biological Control:

A number of diseases and viruses attack barley. The most significant in natural populations are Powdery Mildew and Barley Yellow Dwarf virus which is spread by aphids.

Related plants:

Barley grass (H. leporinum) has much smaller seeds.
Mediterranean Barley grass (H. hystrix or H. geniculatum) has much smaller seeds.
Northern Barley grass (H. glaucum or H. leporinum ssp. glaucum) has black or pale anthers, 0.6 mm long, that remain inside the floret. The anthers are much longer in the lateral florets than the central one. It has much smaller seed.
Sea Barley grass (H. marinum) tends to grow in saline areas and has much smaller seed.

Plants of similar appearance:

Wheat (Triticum aestivum) has smaller auricles that rarely encircle the stem. The grain is not tightly attached to the glumes.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P141-142.

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). P56.

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). #655.7.

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). P965.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P35-36. Diagrams. Photos.

Paterson, J.G. (1977). Grasses in South Western Australia. (Western Australian Department of Agriculture Bulletin 4007). P55.

Acknowledgments:

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