Look for the distinctive maroon bristles

An erect to spreading annual grass with stout branches up to 2 metres high recognisable by the conspicous maroon (purple-red) bristles on the seed head. The flowers and seed heads generally appear between late November and early March. Leaf blades are 10–35 cm long, 7–18 mm wide, flat and generally smooth.

Swamp Barnyard Grass Echinochloa telmatophila is native to Brisbane and found in the coastal areas of Queensland, New South Wales and south-west Western Australia. It grows in wetlands and near creek banks. The Atlas of Living Australia lists an occurance at Pender Street The Gap near Enoggera Creek. Swamp Barnyard Grass may be mistaken for the closely related weeds Awnless Barnyard Grass Echinochloa colona and Common Barnyard Grass Echinochloa crus‑galli. These weeds do not have maroon bristles on the seed head.

Seed head with distinctive maroon (purple-red) bristles. Found at Walton Bridge Reserve, The Gap. Photo: Robert Whyte