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.
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.
Leaves:Three leaflets (trifoliate) with the stalk of the central leaflet longer than those of the side leaflets.
Stems:Low lying, sprawling,
Flower head:A few flowers on the ends of stalks arising from the leaf axils.
Flowers:Yellow pea type.
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.
Physiology:Has an association with Rhizobium in root nodules that fix atmospheric nitrogen.
Seed Biology and Germination:Vegetative Propagules:
Origin and History:Distribution:
Soil:Prefers slightly acid to alkaline soils
Detrimental:Weed of crops.
Toxicity:Not recorded as toxic.
Management and Control:Chlorsulfuron, metsulfuron or triasulfuron herbicides provide high levels of control in cereal crops. Clopyralid can be used in Canola.
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:
Plants of similar appearance:Clovers (Trifolium species) usually have the central leaflet on a stalk the same length as the side leaflets.
References:Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).