Bathurst burr identification
Bathurst burr is an erect, much-branched annual herb, up to 1 m high but usually 30 to 60 cm. Leaves are dark green on the upper surface, a paler green on the under surface, up to 7 cm long and usually three lobed. Stems are branched with one or two three-pronged yellow spines at the base of each leaf stalk. Flowers are creamy green and small, developing into straw-coloured burrs, 1.0 to 1.5 cm long, with numerous yellow hooked spines. Each burr contains two seeds. Of the two seeds present in each burr, only one will germinate in a single season. The other seed will remain dormant for two or three years, sometimes longer.