When you find a yellow mess on your bathroom floor, this isn't exactly the one you expect.
A Sydney resident spotted a new yellow growth in the corner of his bathroom and, understandably, simply had no idea what it was.
On Wednesday he snapped a picture and uploaded it on Facebook, seeking answers from locals in the Willoughby-based community group.
"Does anyone have any idea what this is growing in the corner of my toilet?" he asked.
Internet guesses what strange 'growth' could be
The comments section was quickly full of educated guesses, alongside witty comments, as people offered the confused resident an answer.
"Looks like a new lemon curd donut!" one woman noted, while others questioned if it was a "toilet duck" or a "jellyfish".
Others pointed to the popular television series 'Last of Us', a show which shows the devastating result of a deadly fungus spreading, and jokingly suggested it could be a similar growth from the show.
"It's the start of the apocalypse," one woman wrote, while another opted for a more serious tone, suggesting "a good clean and regular airing" for the "mushroom".
Expert shines light on the bright yellow fungi
The growth inside the man's bathroom has been identified as the fungi known as a Flower Pot Parasol.
As the name suggests its common to spot these inside pot plants and greenhouses, but is "very rare" to be found inside a bathroom, with its presence indicating a larger issue for the resident.
"It's a sure sign that there’s wet wood behind the panelling," Dr Tom May told Yahoo News Australia.
As the Principle Research Scientist of Mycology at the Royal Botanic Gardens Victoria, he explained that these types of fungi feed on decaying matter, such as mulch or wet wood, meaning water has definitely infiltrated the wall and started to cause it to decay.
The Flower Pot Parasol is not toxic unless ingested, however, like other fungi, such as mould, they spread by releasing spores and can easily cause respiratory related issues for occupants inside the property.
“You definitely don’t want a mushroom inside your house releasing spores," Dr May said.
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