Most flexible strongest timber?

Hi everyone,

Just wishing to rack your brains on the most flexible and strongest timber.

I've been told about Osage orange,that it's been used to make longbows, and would be right for what I'm looking for.

I'm looking for a timber that comes in lengths close to 6 foot and has minimal knots.

Does anyone know of any other species which are very flexible, yet still strong.

Thanks