Hairgrass
Aira species
Aira caryophyllea L. Silvery Hairgrass
Aira cupaniana Guss. Silvery Hairgrass
Aira elegantissima Schur
Aira praecox L. Early Hairgrass
Family: - Poaceae.
Names:
Aira is the Greek name for darnel.
Hair grass or Delicate Hair grass, because of its delicate nature and fine hair like stems and seed heads.
Other Names:
Delicate Hair grass
Early Hair grass
Silvery hair grass, Seed heads are silvery in appearance.
Summary:
A fine leaved, hairless, erect annual grass.
Description:
Cotyledons:
One. Fine.
First leaves:
Parallel sided. Narrow.
Leaves:
Emerging leaf rolled in the bud.
Mainly at the base of the stem.
Blade - Grey green. Hairless. Short. Narrow. Sometimes rolled inwards.
Ligule - Conspicuous, membranous or translucent, lance shaped, hairless.
Auricles - None.
Sheath - Smooth or rough to touch. Loose. Striped
Stems:
100-300 mm tall. Single or a tuft of erect stems.
Flower head:
Loose, open panicle. 20-100 mm long. Broadly egg shaped. Branches longer than spikelets. Often with paired slender branches that are initially erect and later widely spreading.
Flowers:
Spikelets - Single at the ends of fine branches. Silvery or pinkish. 1.5-4mm long. Spikelet stalks 2-10mm long. 2 flowered. Flattened.
Florets - 2. Both bisexual. Shorter than glumes. Serrated on the keel.
Glumes - 2, oval, persistent, hairless, membranous, keeled, 1 nerved and pointed.
Palea - 2 lobed.
Lemma - brown, hard, thin and transparent, with a two pointed tip, shorter and narrower than glume and sometimes with a bent awn attached to their back. Rough to touch near the top.
Stamens -
Anthers -
Fruit:
Seeds:
Small. Narrow. Grooved lengthwise on one side.
Roots:
Fibrous.
Key Characters:
Open and lax panicle.
Pedicels (flower stalks) 3-5 times as long as spikelets.
Biology
Life cycle:
Germinates in autumn and early winter following rains. Vegetative growth during winter. Sets seed in spring and dies in summer.
Physiology:
Reproduction:
Flowering times:
September to December.
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Origin and History:
Mediterranean. Europe. Africa. Asia. Azores
Distribution:
ACT, NSW, QLD, SA, TAS, VIC, WA.
Red = Aira caryophyllea L. Silvery Hairgrass
Yellow = Aira cupaniana Guss. Silvery Hairgrass
Blue = Aira elegantissima Schur
White = Aira praecox L. Early Hairgrass
Habitats:
Grasslands.
Climate:
Temperate
Soil:
Gravelly hill slopes and ridges with sandy granitic or skeletal soils
Plant Associations:
Grasses. white cypress pine communities.
Significance:
Beneficial:
Fodder, but doesn't produce much bulk.
Detrimental:
Weed of grasslands.
Toxicity:
None reported.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Herbicide resistance:
None reported.
Biological Control:
Related plants:
Early Hair grass (Aira praecox)
Delicate Hair grass (Aira elegantissima, Aira elegans)
Silvery Hair grass (Aira caryophyllea, Aira cupaniana)
Plants of similar appearance:
References:
Black, J.M. (1978). Flora of South Australia. (Government Printer, Adelaide, South Australia). P161. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P34-37. Diagram.
Ciba Geigy 2 .
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P52. Photo.
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #41.
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). P935.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.