How about this Magnolia Wood? [pr0n inside]

I believe it is not a hard wood. Probably not a good idea to smoke with.

Try sawing it with a manual saw. If it's hard it will be very difficult to saw through.

The magnolia trees that I have trimmed here in Florida, USA, have a somewhat bitter smell and taste (when some of the sawdust falls into my mouth). I would guess that it would have a combination of a bitter and floral smoke flavor. I would try to find out which species of magnolia you might have, then do some research as to potential toxicity. If everything looks good, then do a test burn of a small dry piece. If the smoke smells good, then smoke a single piece of chicken breast to evaluate the flavor.

Personally, for all of the unknowns, I would just burn that wood up in a campfire and find a known good smokewood.

In all the lists I've seen for smoking woods I don't ever remember seeing Magnolia listed as acceptable. Campfire wood IMO.

Our native (southeastern US) sweet gum magnolias & wild gum magnolias are soft and have a very bitter aroma when burned. If you take a piece and let it dry, if large cracks appear within a month or two it is a soft wood. But, try to burn a small piece and see what it smells like. Your nose will tell you very quickly if you want to taste it or not in your cooking.