This is my favorite (although invasive and non-edible) ginger:
(image from http://commons.wikimedia.org/wiki/File:Hedychium_gardnerianum.JPG)
It smells soooo good and there is quite a lot growing around my area, although not on my land, because it really does spread. When I go on a walk when it is blooming, it's very nice.
This is the edible ginger:
(image from: http://commons.wikimedia.org/wiki/File:Shell_Ginger_Variegated_Pink_flowers.jpg)
I haven't seen this growing in my area; we might be too high. You can see they look very different.