Polygonum hydropiper
An annual herb with an ascending stem with slight swelling at the nodes. Grows up to 60 cm tall. Leaves are broadly lanceolate with wavy margins. Drooping flowers are green to red with gold coloured glands. The fruit is a flattened triangular shaped nut. Easily spotted in pasture by the bright, poisonous green colour.
Other Polygonum species, especially redshank.
Common in damp places in pasture. Found from Auckland to Oamaru, but less common further south.
Not identified but extracts of the plant have been lethal to rabbits. May cause contact dermatitis.
Livestock, humans and rabbits have been affected.
Gastrointestinal irritation and inflammation
Evidence of plant ingestion and gastrointestinal irritation.
Symptomatic.
Avoid grazing hungry animals where the plants are growing.
Conner H.E. The Poisonous Plants In New Zealand. 1992. GP Publications Ltd, Wellington
Cooper M R, Johnson A W. Poisonous Plants and Fungi in Britan: Animals and Human Poisoning. Her Majesty’s Stationary Office. London. 1998
Parton K, Bruere A.N. and Chambers J.P. Veterinary Clinical Toxicology, 2nd ed. 2001. Veterinary Continuing Education Publication No. 208
