Annual, spreading by seed, it is not a grass as the common name might suggest, but is a member of the Polygonaceae Family. The wirey branched stems have 'knots' at leaf joints which are
swollen with a covering silvery scale. The lance-shaped leaves have a short
stalk. The sap can be irritant to the skin, but it has styptic properties and the crushed leaves have been used to staunch a nosebleed by rubbing into the nostrils.
Hoe or hand pull, tough branching tap-root, giving rise to other name,
Iron-grass. Applying mulch to newly cultivated bed should prevent germination.
Paraquat, Diquat kill on contact. Glyphosate will also work, but the delayed action may allow seeds to be shed if the plants are near maturity.