People are grossed out after learning a common tree in the US lets off a VERY rude smell... have you come across it?

The ornamental pear tree might be America's most controversial. 

Its pretty white spring blooms, attractive shape and cheapness have made it popular since its arrival in the US in the early 1900s.

But beware, anyone who lives near one will tell you about the very rude, putrid smell that it lets off in the summer time.

One DailyMail.com reader who wrote in revealed how he had been visiting his wife's parents in London when he first experienced its stench.

The couple had been walking the dog and every now and then would be assaulted by what they described as a 'foul smell... almost like semen'.

Upon their return to the States, they found the source of the smell was the ornamental pear tree, also known as the callery pear tree. When they began Googling it, they were shocked that the problem is being felt across the US. 

Although the callery pear tree's flowers are often seen as beautiful, they also contain compounds called volatile amines, trimethylamine and dimethylamine that gives off a 'fetid, dead-animal odor that can smell like semen

Although the callery pear tree's flowers are often seen as beautiful, they also contain compounds called volatile amines, trimethylamine and dimethylamine that gives off a 'fetid, dead-animal odor that can smell like semen

Dozens of Reddit threads, horticulturist magazines and local and national stories have been written about the callery pear tree's foul odor.

Although the tree's flowers are often seen as beautiful, they also contain compounds called volatile amines, trimethylamine and dimethylamine that gives off a 'fetid, dead-animal odor,' according to the Missouri Department of Conservation.

These compounds are similar to those found in ammonia, which is also in semen.

Others have described the odor as reminiscent of fish, cleaning spray or decaying flesh.

When the weather is warm and the tree is in bloom, these smells become noticeable in the air.

These trees are an invasive species native to Asia that grow in China and Taiwan with flowers that are meant to attract insects like blow flies which pollinate the trees.

The tree was brought to the US from China in the early 1900s, but grew in popularity in suburban developments in the 1950s.

Because these trees can grow in any type of soil and were attractive to flies and birds, their seeds spread across the country.

People have taken to Reddit to complain about the trees' odor, with one person writing: 'F***ing hate these trees, they were all over my college campus. 

'Like, the least you could do is produce a pear every now and then, but no, instead we just get cum stank for three months a year.'

Some states have moved to ban people from buying, planting or selling the callery pear tree because of it's rancid odor

Some states have moved to ban people from buying, planting or selling the callery pear tree because of it's rancid odor

Some states like Ohio have banned the odiferous plant after locals complained about the horrid smell, making it illegal to buy, sell or plant additional callery trees as of January last year. 

South Carolina and Pennsylvania have also banned the tree while Michigan is in the midst of considering following in their footsteps.

The trees aren't beneficial for the ecosystem because they don't produce eatable fruit and aren't an adequate food source for bugs and animals.

'Everybody has a different description, some of them more PG than others,' Katie Grzesiak, a terrestrial invasive species coordinator for the Michigan Department of Natural Resources told News 8

'I think it smells like dog poo. Other people might say fish. Others have said rotten meat. It's not pleasant.'