One of the authors of the study, Professor Stephen O’Leary, said while it might sound strange that a plant could pose such danger to people, it was no laughing matter. “You wouldn’t think that a little pointy leaf that goes into your ear could possibly cause serious injury [but] it’s more like a fencing sword; it’s narrow enough to get right down through the ear drum,” Professor O’Leary said. “Most of us were surprised when we started getting these cases through, but then we looked back and thought, hang on, this is happening a lot. “And it can go really wrong indeed.” Eye and Ear Hospital doctors and article co-authors Adrian Dragovic and Maria Vartanyan examine a yucca from a safe distance. Credit:Joe Armao

Most cases seen by the Eye and Ear Hospital over five years involved a perforated eardrum, and in four of the most severe cases the yucca penetrated the inner ear, causing fluid to leak out. In all of these four cases the patients suffered permanent hearing loss. The case series is the largest to date examining yucca ear injuries, with the only other reports from Israel in 2009, where there were three cases over seven years. Stephen Ryan, former host of Gardening Australia and owner of Dicksonia Rare Plants in Mount Macedon, said yucca plants were popular because they suited a lot of modern architecture and were easy to grow. “They’re virtually impossible to kill. They’re tough as billy-o, even the most novice gardener would struggle to kill a yucca,” Mr Ryan said.

“If you go to most of the newer suburbs of Melbourne, it would seem everything has to have a strappy or spiky, long, narrow leaf because that’s what they seem to make their whole gardens out of. “I think the people who plant those kind of gardens, including yuccas, are doing so to plant something that they don’t actually have to think about.” Landscape architect Andrew Laidlaw said he would not want to give the yucca plant a bad rap, as there are many varieties. “The yucca flower is edible and is a lovely garnish,” he said. “Of course, the fabulous Joshua tree is a yucca.

“They may be a little dangerous, but they are a great garden plant. The worst offender is the yucca elephantipes that [are] sold as the indoor plant. This is the plant that would cause most of the injuries.” Professor O’Leary said it was not yet clear how people were getting injured, but theorised that in an attempt to shield their eyes from the yucca leaves while moving a plant or gardening, they may have turned their ear towards it. He said it was critical for the public to know that if they were dizzy after being stabbed by a yucca leaf the injury needed to be treated as a medical emergency, and that GPs and emergency physicians should also be aware of the risk. The yucca is the only plant to be involved in injuries presenting to the hospital (which often sees eye trauma from magpie attacks). But Professor O’Leary didn't think people needed to get rid of their yuccas, suggesting instead that they might do what he has done with his yucca plant at home – trimmed it in places where it might get in the way.