A small tufted annual rush that often forms carpets in wet areas and turns red-brown when it dies with the onset of drought
Description:
Cotyledons:
One.
First leaves:
Small and narrow, channelled on the inside. Tip pointed. Hairless.
Leaves:
Fine, shiny, flat, channelled, thread like, grass like, 45-140 mm long by 0.2-1.5 mm wide, not septate. Tip pointed. Hairless. 1-3 leaves are on the stem the rest from the base. Erect basal bract, 15-75 mm long.
No ligule, auricles or sheath because it is not a true grass.
Stems:
Tufted, slender, fine, angular or slightly flattened, erect, 20-300 mm tall by 0.2-1.5 mm wide, branched, not septate, base not thickened. Hairless. Form a cushiony mat on the soil when dense. 1-3 leaves are on the stem. All stems bear flowers.
Flower head:
Single flowers or clusters up to 8 mm wide of 2-6 flowers, along spike like branches of the 15-120 mm long panicle from the ends of stems or branches. Cluster become wider when in fruit. It sometimes appears to be in leaf axils. Leafy bracts usually shorter than panicle but occasionally longer at the base of the panicle. The panicle is often the greater part of the plant.
Flowers:
Usually pale when single or red-brown when in clusters. Individual flowers 2 mm wide. 2 papery bracts at the top of the flower stalk (pedicel) enfold the base of each flower. Bracts also at the base of the pedicel. Some forms may be sessile. Cleistogamous.
Perianth - Segments narrow lance shaped, pale green or brown with papery translucent edges and a pointed tip. The outer three are 4-8 mm long with a keel that turns brown. Inner three shorter and 3-5 mm long.
Ovary - Style up to 1.5 mm long.
Stamens - 3 or 6, 2-3 mm long
Anthers -0.7-1.2 mm long.
Fruit:
Red-brown, oblong to elliptical capsule, usually shorter than the perianth.
Seeds:
Many, egg shaped to elliptical, 0.3-0.5 mm long, not tailed. Surface, smooth and hairless.
Roots:
Fibrous and weak. Easily uprooted.
Key Characters:
Stem leaves present. Flowers bracteolate. Flowers terminal and single or in small clusters. Leaves solid, dorsi-ventrally flattened, not septate. Small annual.
Biology:
Life cycle:
Annual. Germinates autumn and winter and grows until soil dries. Flowers from spring to summer.
Physiology:
Reproduction:
By seed.
Flowering times:
Spring to early summer in western NSW.
Throughout the year in SA.
August to January in WA.
Seed Biology and Germination:
Vegetative Propagules:
None.
Hybrids:
Several hybrids, forms and varieties including var. fasciculatus.
In WA there appears to be two types; a slender few flowered variety that is probably native and an aggressive, low lying, robust type that is probably introduced.
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed.
Origin and History:
Probably native and introduced varieties.
Distribution:
ACT, NSW, QLD, SA, TAS, VIC, WA.
Habitats:
Climate:
Temperate.
Soil:
Most abundant on winter waterlogged or damp soils.
Plant Associations:
Significance:
Beneficial:
Fodder with poor production.
Detrimental:
Weed of crop causing yield reductions due to competition.
Weed of rotation crops, perennial crops, gardens, pastures, drains, fallows and disturbed areas.
Toxicity:
Not recorded as toxic.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Herbicide resistance:
Biological Control:
Related plants:
Blunt flowered Rush (J. subnodulosus)
Bulbous Rush (J. bulbosus)
Common Rush (J. usitatus)
Dwarf Rush (J. capitatus)
Giant Rush (J. ingens)
Jointed Rush (J. articulatus)
Jointed Rush (J. holoschoenus)
Pale Rush (J. pallidus)
Sea Rush (J. kraussii)
Spiny Rush (J. acutus)
Tussock Rush (J. aridicola)
(J. effusus)
Plants of similar appearance:
References:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P29-30. Diagram.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P181-182. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P94, 101. Diagram.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P177. Photo.
Gilbey, D. (1989). Identification of weeds in cereal and legume crops. Bulletin 4107. (Western Australian Department of Agriculture , Perth). P58. Photos.
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). P38-39. Photo.
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). #703.4.
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). P867.