Erect, much-branched annual herb <1m high, branched taproot. Small creamy green flowers (Mar-Apr). Alternate, lobed leaves <7cm in length, shiny, dark green topside, downy, pale green underside. Straight spines on greenish-yellow stems & hooked spines on burs. Plants die off in early winter after producing burs.
Prefers high fertility, moderately warm situations: pasture, wasteland, coastal areas, disturbed sites. Common around stockyards, gates, races.
Burs catch in wool, hides, clothing, also via waterways 50% of seeds remain dormant for 2-3 years.
Burs contaminate wool, break shearing combs. Plant spines damage feet of stock. Burs cause skin irritations & dermatitis in some people. Seedlings poisonous to stock. Fungal host in horticultural crops. Contaminates maize & sorghum seed.
Avoid soil disturbance & bare ground. Maintain good pasture cover to prevent re-establishment. Replant with native species where appropriate.
1. Grub out plants before flowering (Mar-Apr).
2. Spray before plants set seed (1g metsulfuron + 20ml penetrant/10L or 120ml Tordon Gold/10L or 25ml clopyralid/10L or 100ml glyphosate/10L). Do not use clopyralid in home gardens.
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.