The largest single flower in the world, and also the worst smelling, is the Rafflesia Arnoldii, or as it is more commonly known, the “corpse flower.” You get one guess as to what it smells like. That’s right, decaying flesh. This is probably not the flower you would want to grow in your garden unless you really, really don’t like company. They are pretty rare and are usually only found in the Asian rainforests.
My Bookish Life 
I would classify that as a weed==undesirable plant! It is pretty though!