Madrone wood is a hardwood with a closed cell structure; when cut fresh it often contains 60% water, resulting in significant shrinkage during the drying process  - over 12 % tangential, and over 5% readial. When left to its own, the wood will wrapp and certainly show cracks prohibiten its use in wood turning. 

Woodturniers have tried various approaches to reduce or eliminate cracking with various success.

Some Turners like myself do take the tension out of the wet wood by boiling it for a few hours. It sounds counterproductive, but when done correctly it produces great results (cook it for at least 4 hours, make sure the wood is steaming after taken out at the right temperature - too hot and it cracks from the steaming moisture, too cold and it may mold and discolor while drying)