Open (my mind,) sesame

I was eating a cheeseburger from a burger place today, and it (the burger) had a sesame seed bun. I realized that I have always taken sesame seeds for granted, in the sense that I've just always irrationally believed that they just sort of come from out of nowhere.

So I began to wonder, is there a sesame flower? A sesame tree with a sesame fruit? Where do these seeds come from, and what would they grow into were it not for the fact that they were diverted to my hamburger bun?