Not too farfetched actually, being related to deadly nightshade.
Of course, the Giant Stinging Tree doesn’t hold a candle to the Upas Tree.
well, there’s the Upas Tree :
http://www.godecookery.com/mythical/mythic02.htm
And the Man-Eating Tree :
Man-eating tree can refer to any of the various legendary carnivorous plants large enough to kill and consume a person or other large animal.
The earliest known report of a man-eating tree originated as a literary fabrication written by Edmund Spencer for the New York World. Spencer's article first appeared in the daily edition of the New York World on 26 April 1874, and appeared again in the weekly edition of the newspaper two days later. In the article, a letter was published by a purported G...
(Willy Ley wrote a great essay about this. It’s in, among other collections, Willy Ley’s Exotic Zoology , even though it’s a plant.)