Murex Medic

Medicago murex Willd.

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.

Other Names:

Zodiak Medic

Summary:

A low lying, hairy, annual medic with trifoliate leaves with triangular, toothed leaflets with red and grey blotches and indented tips and the central leaflet on a longer stalk. The burr is a coiled spiny pod produced from yellow, pea type flowers.

Description:

Cotyledons:

Two. Long and narrow, club shaped. Tip rounded. Edges smooth. Base tapered. Short petiole. Hairless.

First leaves:

First leaf single. round to oval. Tip flat with a tiny spine. Edges toothed. Base squarish. Hairy on the back. Irregular grey-white blotches on both surfaces. Long petiole.
Second and later leaves trifoliate.

Leaves:

Three leaflets (trifoliate) with the stalk of the central leaflet longer than those of the side leaflets.
Stipules - Deeply toothed.
Petiole - Long and hairy.
Blade - Of leaflets triangular. Tip flat or indented with a tiny point. Edges toothed. Base tapered. Irregular white to red-grey blotches on the upper surface.

Stems:

Low lying, sprawling,

Flower head:

A few flowers on the ends of stalks arising from the leaf axils.

Flowers:

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

Fruit:

Pod that is coiled into a cylindrical burr with an anticlockwise spiral, 5-6 mm diameter x 8-10 mm high with low lying spines.

Seeds:

Light brown, kidney shaped, flattish. 2-4 mm long x 1-2 mm thick. Tip slightly rounded. Edges concave or convex. Base slightly rounded. Surface hairless.

Roots:

Taproot with nitrogen fixing nodules.

Key Characters:

Cotyledons club shaped.
First leaf round to oval 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. Seeds germinate from autumn to winter,

Physiology:

Has an association with Rhizobium in root nodules that fix atmospheric nitrogen.

Reproduction:

By seed.

Flowering times:

Spring.

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed and intentional plantings.

Origin and History:

Distribution:

ACT, NSW, NT, QLD, SA, TAS, VIC, WA.
Not naturalised.

Habitats:

Climate:

Temperate.

Soil:

Prefers slightly acid to alkaline soils

Plant Associations:

Significance:

Beneficial:

Fodder.

Detrimental:

Weed of crops.

Toxicity:

Not recorded as toxic.

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Chlorsulfuron, metsulfuron or triasulfuron herbicides provide high levels of control in cereal crops. Clopyralid can be used in Canola.
Tolerant to grazing.

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.

Herbicide resistance:

None reported. It is relatively tolerant to glyphosate.

Biological Control:

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)
Murex Medic (Medicago murex)
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).

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume . P. Diagram.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P88. Diagrams. Photos.

Acknowledgments:

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