A Hawke's Bay woman's afternoon of gardening left the landscape looking fine but cost her the sight in one eye for about five days.
"I want to put out a little warning here," Jenny Connor of Crownthorpe said.
"People need to be very careful with it."
"It" is the plant genus known as euphorbia which covers about 30 different species, including some common ones like decorative poinsettias.
While the leaves and flowers of most of the species are fine, the latex fluid contained in the stems of some is not.
In some forms of euphorbia which grow in South America the latex is extracted and used to tip poison darts.
Mrs Connor had been gardening about 10 days ago and after pruning a bush went inside and washed her hands as usual.
But it was a few seconds later when she brushed the back of her hand over one eye that she was immediately struck by what she called "excruciating" pain.
"My eye went blood red and I lost sight in it."
She immediately went to see her doctor who urgently referred her to a specialist as he had not come across anything like it.
She was put on a course of treatment using cortisone drops and simply had to wait for the poison and inflammation to dissipate - which it did five days later.
"I was very worried at the time," she said, adding that two family members had lost their sight late in life and she thought she was about to be another.
She said it appeared some of the latex fluid from a plant had got on to the back of her hand and she had missed it while washing.
"Anyone out gardening needs to wash thoroughly with soap and water all over their hands - get everything off them."
She consulted websites and discovered how widespread euphorbia plants were around the world, and across this country.