That's what I was going to say too. From what I've read historically on native american archery, some bows were "medicine bows" and used for ceremony, and not actual use. Another example of this are bows the buffalo hunters made out of pure rib, or horn, with no wood at all.
In the movie Dances With Wolves, there is a long (looks like 5-6 feet) skinny bow in the medicine man (Kicking Bird)'s tipi. It is somewhat decorated and I believe can be seen at one other time in the movie. Check it out and see if you see what I'm talking about.
~Matt