The summer holidays are another reminder New Zealand's great
outdoors is populated by plants which can cause harm if
eaten, leading to a stinging mouth, sore stomachs, vomiting,
itchy and painful skin or more serious poisoning.
The National Poisons Centre, in Dunedin, has analysed more
than 11,000 inquiries it received after people came into
contact with or ate poisonous plants or fungi.
Many of the most commonly plants inquired about - such as
kowhai and arum lily - cause only mild symptoms, such as an
upset stomach or burning mouth.
But a handful, including foxglove and oleander, require
immediate medical treatment if eaten.
Poisons centre toxicologist Dr Leo Schep said calls were
mostly made after young children ate plants.
Parents should know the plants in their garden and
neighbourhood and avoid or get rid of potentially poisonous
ones, he said.
The bright yellow of daffodils - which contain toxic
alkaloids - were too appealing for 56 children and 28 adults,
the centre's records for 2003-10 show.
The flower itself would cause only vomiting, but eating the
bulb would require a hospital visit, Dr Schep said.
''Also, surprisingly, people drink the water that the plants
have been in. Kids will do anything.''
Black nightshade was the most common poisonous plant inquiry,
with 834 calls - 90% of which related to children.
The green, unripe berries of the common weed contain toxic
alkaloids and can be mistaken for peas.
The plant was not to be mistaken for the similarly named
deadly nightshade, which was extremely rare in New Zealand,
Dr Schep said.
Because the green berries were low in toxicity, a 12kg
2-year-old would need to eat about 36 before there was any
need for concern, Dr Schep said.
Arum lily caused a stinging of the mouth if eaten, but not
serious poisoning. Kowhai was not a concern because the toxic
seeds were encased in a hard shell: ''You swallow it and it
just goes straight through your system.''
The fourth-most-common plant inquiry was about euphorbia or
''spurge'' - herbs or shrubs which have a highly irritating
white, latex-like sap.
More than 100 calls to the centre were about eye exposure to
the sap, which if left untreated can result in blindness.
Ongaonga, or New Zealand tree nettle, which can grow to 2m
high, causes intense pain with itching after contact with the
skin. Dogs have died after exposure.
Dr Schep flagged karaka, foxglove, hemlock and oleander as
the most dangerous plants, particularly for toddlers.
Foxglove and oleander contain a toxin which can bring on
serious cardiac issues, and can be treated with charcoal.
''If you've got kids and you've got an oleander tree in your
property, it may be worth getting it bowled. And foxglove -
get rid of it,'' Dr Schep advised.
The native karaka evergreen tree contains a toxin, karakin,
which is most concentrated in its kernels. Small amounts of
human ingestion were unlikely to cause serious poisoning, but
dogs had died after eating the kernels, Dr Schep said.