Here's a picture of some magnolia seedlings, and a michelia is basically a magnolia. So, you'll have to be very lucky.
http://outdoors.webshots.com/photo/1...34280845pOqKhl

I think Pam might have got it right with her second guess.

Reminds me of the time I sowed some Meconopsis betonicifolia, blue poppies. What came up looked rather like birch. But then "betonicifolia" means "birch-leaved", so I held on hopefully. But of course it was birch. In fact I grew a few on and still have one of them, now about 10 feet tall.

I find my indoor pot-plants occasionally get weeds in them. Even if the composting killed everything off, I don't think that they keep it in perfect biological security before packing it.