Cooking Floyd: Curry Powder

I was asked recently what curry is.  There are several definitions of curry.  There is the leaf from the curry tree that grows in South India and plays a huge role in that region's foods.  It can be found here in shops specializing in Indian ingredients or online.  There is the "curry plant" that's showing up in nurseries in the spring.  Smells like curry, tastes terrible.  Great for potpourri, horrible for cooking.  Curry is a South Asian/Indian dish with a sauce or gravy as opposed to a dry stir-fry type dish which is not.

And then there is the spice, curry powder, which I think is what I was being asked about.

 Curry powder is not just "a" spice, but a blend of spices.