Zantedescia aethiopica
lily of the Nile (nb. Agapanthus species are also called Nile lily), white arum lily, calla lily
1.5m tall plant growing from rhizomes with large arrow head shaped leaves. Large flowers in spring and early summer. Natural type has white flowers, but various hybrids may have yellow or orange flowers and spotty leaves.
There are a range of other related plants grown in gardens; most are probably toxic. Elephant’s ear is relatively common in the North Island, taro is sometimes seen in Northland.
Native of South Africa, widely escaped from cultivation in the North Island. Prefers damp, shady spots, but often seen growing in the middle of fields.
Calcium oxalate raphides cause initial injury which allows the proteolytic enzyme dumbcain to enter damaged tissues. Not very poisonous.
Most reports concern horses, but all species may be affected. Poisoning is rare, despite the plant being common.
Clinical signs are similar to hypocalcaemia. Other signs include ataxia leading to recumbency, nasal discharge, muscular spasms and dyspnoea caused by pulmonary oedema from capillary damage.
Rare (requires a long period of plant ingestion): kidney damage and failure leading to death.
Severe pulmonary congestion with copious froth in trachea and bronchi, gut hyperaemia and swollen kidneys with pale cortex.
Leaves in stomach, calcium oxalate crystals in kidney.
Other poisonous plants, especially those containing oxalates. Docks, rhubarb, taro, elephant’s ear, oak. Other causes of acute respiratory failure.
As for other plants containing oxalates. Fluids and calcium borogluconate IV.
Poor if signs are seen the animal may die later from respiratory failure despite initial improvement.
Connor, HE, The Poisonous plants in New Zealand, 2nd ed.,1977, Government Publications Ltd., Wellington
The Merck Veterinary Manual, 8th ed, 1998, Merck and Co., New Jersey
Upritchard, E.A., A Guide to the Identification of New Zealand Common Weeds in Colour
