Colocasia esculenta
Leaves are up to three on each stalk, heart shaped with a slightly wavy margin. Corm is cylindrical, up to 20cm long and up to 1cm in diameter. May have smaller accessory cormels attached. The outside of the corm is rough, brown and hairy.
Arum lily tops look similar.
Native to the tropical rainforests of Asia and Africa. Grown as a cultivated vegetable in the tropics and sub-tropics. Can be found in the north of the North Island.
Leaves contain oxalate crystals and a proteolytic enzyme. Oxalate crystals are very irritating to the mouth, esophagus and stomach. When circulating in the blood can cause severe damage to the pulmonary capillaries and cause pulmonary oedema. Chronic oxalate intake causes crystals to precipitate out in tubular lumen of the kidney causing renal failure. Acute, high intake of oxalate binds blood calcium and can cause hypocalcaemia and death. Phytic acid is also present in leaves, which binds to blood calcium to decrease serum calcium even further. Parts poisonous: Leaves and stems, apparently no seasonal occurrence.
Mostly cats and dogs although all species can be affected.
Dyspnoea, diarrhoea, dehydration and shock have been reported.
Finding plants in vomit, low serum calcium and high BUN/creatinine if kidney failure occurs.
Poisoning with other oxalate plant such as sheep’s sorrel or rhubarb leaves. Milk fever.
Give milk or lime water which may help to bind soluble oxalates in the gut.
Recovery is slow over 8-10 days but prognosis is good provided good supportive therapy.
Conner H.E. The Poisonous Plants In New Zealand. 1992. GP Publications Ltd, Wellington
Parton K, Bruere A.N. and Chambers J.P. Veterinary Clinical Toxicology, 2nd ed. 2001. Veterinary Continuing Education Publication No. 208
4 October, 2007