Broad-leaved Carpet Grass
Axonopus compressus (Sw.) P.Beauv.
Family: - Poaceae.
Names:
Broad leaved Carpet grass.
Other Names:
Flat Jointgrass
Savannah grass
Summary:
A perennial, stoloniferous, carpet forming, hairless grass. 150-600 mm tall.
Description:
Cotyledons:
One
Leaves:
Hairless but there may be a few hairs where the blade joins the sheath and along the edge of the blade.
Blade - Flat or keeled. Striped. Narrowly egg shaped to parallel sided. 80-250 mm long by 60-120 mm wide. Flattened and folded along the obvious midrib. Rarely with hairs on the upper side, never hairs on the lower side, hairs on the edges.
Ligule - short membranous rim that is flat on top and is usually fringed with fine hairs.
Sheath - flattened, keeled. Striped. Often have a purple tinge. Edges are translucent. Deeply split. Hairless or rarely hairy on the edges.
Auricles - None.
Stems:
Slender or in tufts. 1-3 nodes. Nodes are densely hairy.
Flattened. Often purplish. Nodes often hairy.
Flower head:
Main axis (rachis) is triangular with concave faces giving 3 distinct lengthwise ridges. Usually 2 or 3 branches, with the upper 2 paired and one longer than the other.
Spikes - 2 or 3 usually (less than 5). No stalk. Slender. Erect or spreading. 40-100 x 1-15mm.
Flowers:
Spikelets - Single, one flowered. Oval to egg shaped. Erect. Green or purplish. Alternate and held close to the stalk. 2.2-3.5 mm long by 1 mm wide.
Florets - Bisexual one, oval to oblong, rounded top, shorter than spikelet.
Glumes - Upper one, oval to egg shaped, 2-4 ribs near the edges, middle is papery.
Palea - Bisexual one, hard, thin and brittle.
Lemma - Empty one similar to glume. Bisexual one hard, thin and brittle.
Stamens -
Anthers -
Seeds:
2.2-3.5 mm long by 1 mm wide.
Roots:
Creeping stems that root at nodes. Fibrous underground roots. Occasionally forms rhizomes.
Key Characters:
Biology:
Life cycle:
Perennial.
Physiology:
Reproduction:
Flowering times:
October to March.
Seed Biology and Germination:
Vegetative Propagules:
Stem fragments.
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spreads by creeping stems that root at the nodes.
Origin and History:
Tropical America.
Introduced as a lawn grass.
Distribution:
NSW, QLD, WA.
Courtesy Australia's Virtual Herbarium.
Habitats:
Warm moist areas. Intolerant of drought.
Climate:
Soil:
Plant Associations:
Significance:
Beneficial:
Lawn grass
Spring and early summer fodder grass.
Detrimental:
Weed of other lawns, poor pastures, rotation crops, disturbed areas and grassland.
Toxicity:
None reported.
Legislation:
None.
Management and Control:
Thresholds:
Eradication strategies:
Herbicide resistance:
Biological Control:
Related plants:
Narrow leaved Carpet grass (A. affinis).
Plants of similar appearance:
Narrow leaved Carpet grass (Axonopus affinis) has longer, narrower leaves and longer flowering heads and no hairs on the leaves. The fertile lemma is 0.8 x the length of the spikelet whilst in Axonopus compressus it is the same length.
Summer grass (Digitaria sanguinalis) has hairy leaves that distinguish it from Carpet grass.
References:
Ciba Geigy (1980) Grass Weeds 1. CIBA GEIGY Ltd, Basle, Switzerland. P10. Diagrams.
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #153.2.
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). p942.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.