Charlie wrote:

You can buy flooring made from bamboo from lots of flooring dealers. I
wondered about whether it was available in long enough pieces, but it
looks like it is.

http://floorus.com/Bamboo6FPro.aspx

Question is, whether it's stiff enough to make a good prop.

It is an interesting idea, though. The grain should be very straight &
consistent.

Charlie

The answer, of course, is another question.
What is the propeller being asked to do?