Apple and Tree

Adam and Eve by Albrecht Dürer (1507)

This particular myth has been perpetuated in western art for centuries. That the narrative given in the Bible, the Qur'an, and the Torah says that the forbidden fruit was an apple. 

Do they say apple?

Nope, there is no mention of apples in Eden. 

In fact, historically it was held that the forbidden fruit was figs. Or possibly grapes. Or maybe a pomegranate. Unless it was an etrog. [*] Though it could have also been a banana. [**]

...The point is, it doesn't say anywhere in Bereshit / Genesis / the Koran what the fruit is, and nobody really knows. 

So how did apples get wrapped up in it? 

It was a pun. You see, in Latin mălum means "evil" while mālum means "apple." 

It was an evil tree; it was an apple tree. 

Yep. A thousand years worth of art on the Latin equivalent of the "orange you glad I didn't say banana?"  line.