Just call me Alton Brown...

So ... what, exactly, is the different between a Sweet Potato and a Yam??

I don’t know why I asked my father this question yesterday, but the answer was fairly surprising, so I thought I should share this with all of you. And yes, I know that the fact that I have even asked this question is probably a warning sign … but you all didn’t expect me to become more normal with time … did you?

The answer plunges us into a Matrix-like underworld in which nothing is as it seems:
Turns out, there is no Yam ….Everything sold in the US, whether called a “sweet potato” or a “yam” is actually a sweet potato.

But perhaps more disturbingly, sweet potatoes are actually MORNING GLORIES??

Freaky:

Sometimes I think I'd be better off not knowing these things.