Puh-Kahn or Pee-can? Which one?

An old friend of mine that I haven’t seen in years stop by my house to visit. He owns a small trucking company based out of Minnesota and he just happened to be in the area. While we were sitting out on my back patio talking, he couldn’t help but notice the large “puh-kahn” tree that shades the patio during the summer months. He asked me what kind of tree is that. I told him its a “puh-kahn” tree. He said no, you mean its a “pee-can” tree. I said no, you damn yankee, its a puh-kahn tree.

So what’s the correct pronunciation?