How to Identify Knotgrass (irongrass) (Polygonum aviculare)
Height x spread: Up to 60 x 150cm (2 x 5ft).
Leaves: Lance-shaped; silver sheath around stalk base.
Flowers: Small, pink and white, in clusters at base of leaves, summer to autumn.
Other features: Germination mainly in early spring. Branching stems trail or scramble. Annual.