Strand Medic

Medicago littoralis Loisel.

Synonyms -

Family: Fabaceae

Names:

Medic is from the Latin medica meaning Lucerne and derived from the Greek mediche because it was introduced to Greece from the Media region in the Old Persian Empire.
Herald Strand Medic
Angel Strand Medic is a cultivar that is tolerant to group B herbicides.

Other Names:

Summary:

A low lying to ascending, hairy, annual medic with trifoliate leaves with round to triangular, toothed leaflets without markings and the central leaflet on a longer stalk. The barrel-like burr is a coiled, spineless or short spined pod produced from yellow, pea type flowers.

Description:

Cotyledons:

Two. Club shaped. Tip round. Sides convex. Base tapered. Surface hairless. Petiole shorter than the blade and merging with it.

First leaves:

First leaf single, heart shaped. Tip round, Edges smooth, irregular, scalloped or toothed. Base indented, Hairy. Petiole longer than blade. Second and later leaves trifoliate.

Leaves:

Three leaflets (trifoliate) with the stalk of the central leaflet longer than those of the side leaflets.
Stipules - Pale green with darker veins. Edges deeply toothed.
Petiole - Longer than leaf blade, Hairy.
Blade - Of leaflets. Round to triangular. Tip flat to pointed. Edges toothed. Base tapered. Hairy. No leaf markings.

Stems:

Low lying or bending upwards. Hairy.

Flower head:

Clusters of flowers and burrs on a long stalk arising from the leaf axils.

Flowers:

Yellow pea type.
Ovary -
Calyx -
Petals - Yellow.
Stamens -
Anthers -

Fruit:

Coiled, burr like pod, cylindrical or flat round disk with flattened ends. 4-5 mm diameter x 4 mm tall. May have short spines.

Seeds:

Light brown, kidney shaped, slightly flattened with squarish ends, 3 mm long x 1-2 mm wide. Tip round to square. Edges concave or convex. Base round to square. Surface hairless. High levels of dormancy.

Roots:

Taproot with nitrogen fixing nodules.

Key Characters:

Cotyledons club shaped.
First leaf heart shaped.
Older leaves trifoliate with the terminal leaflet on a longer petiolule than the side leaflets.
Yellow pea type flowers.
Coiled burr.

Biology:

Life cycle:

Annual herb. Seeds germinate in autumn and winter.

Physiology:

Dry matter production is around 3000 kg/ha.
The Angel cultivar is tolerant to soil residues of group B herbicides such as triasulfuron, chlorsulfuron and sulfometuron. It also tolerates post emergent applications of imazamox, imazethapyr, imazapic, imazapyr. Low rates of sulfometuron have little effect on herbage yield but do delay flowering and reduce seed yield. It is not particularly tolerant to post emergent sulfonylurea herbicides such as chlorsulfuron and metsulfuron.

Reproduction:

By seed.

Flowering times:

Spring.

Seed Biology and Germination:

High levels of dormant seed. It generally takes 1-2 seasons for good natural regeneration.
Around 650 kg/ha of seed can be produced in field situations which produce initial seedling densities of 1000-1500 per square metre.

Vegetative Propagules:

Hybrids and Cultivars:

Angel is a cultivar that is tolerant to group B herbicides.
Herald is a parent of Angel.

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed and intentional plantings.

Origin and History:

Mediterranean.

Distribution:

NT, SA, TAS, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.
Well adapted to 250-400 mm annual rainfall areas.

Soil:

Prefers alkaline soils.

Plant Associations:

Significance:

Beneficial:

Fodder.

Detrimental:

Weed of crops and roadsides.

Toxicity:

Not recorded as toxic.

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Chlorsulfuron, metsulfuron or triasulfuron herbicides provide high levels of control of normal cultivars in cereal crops, however Angel cultivar is tolerant to these and hormone herbicides provide better control. Clopyralid can be used in Canola.
It is tolerant to grazing and mowing.

Thresholds:

More than 20 plants/m2 is usually worth controlling in cereal crops.

Eradication strategies:

In bushland situations, Logran® at 40g/ha provides reasonably selective control of normal cultivars. Use 150 g/ha Lontrel® 750 if the Angel cultivar is present.

Herbicide resistance:

None reported. It is moderately tolerant to glyphosate.
Angel cultivar is tolerant to group B herbicides.

Biological Control:

Susceptible to Redlegged Earth Mite.

Related plants:

Barrel Medic. (Medicago truncatula)
Black Medic (Medicago lupulina)
Burr Medic (Medicago polymorpha, Medicago hispida)
Button Medic (Medicago orbicularis)
Calvary Medic (Medicago intertexta)
Cutleaf Medic (Medicago laciniata)
Disc Medic (Medicago tornata)
Gama Medic (Medicago rugosa)
Lucerne (Medicago falcata ssp. sativa)
Lucerne (Medicago sativa)
Small leaved Burr Medic (Medicago praecox)
Snail Medic (Medicago scutellata)
Spotted Medic (Medicago arabica)
Strand Medic (Medicago littoralis)
Woolly Burr Medic (Medicago minima)
Yellow Lucerne (Medicago falcata)

Plants of similar appearance:

Clovers (Trifolium species) usually have the central leaflet on a stalk the same length as the side leaflets.
Melilotus species
Oxalis species usually have a bitter taste.
Trefoils

References:

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Howie Jake. (2007) Tolerance of 'Angel' to Group B Herbicides: Part II - Foliar Applied.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (2007). Western Weeds. A guide to the weeds of Western Australia. (Second Edition). Plant Protection Society of Western Australia, Perth, Western Australia. P158.

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #638.8.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P86. Diagrams. Photos.

Acknowledgments:

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