Tree Id--small round greenish flowers and seedheads

We Master Gardeners were asked to identify this tree. Apparently this was one that was brought in to Saudi Arabia 30 years ago and planted at an industrial complex to help with pollution. My guess is that it's some kind of Australian shrub/tree. It's apparently evergreen and can grow to 30 feet if it's not pruned back. See attacked photos. The closest thing we can find is Cephalanthus, and that's not right... Thanks for looking at this for us!

 

Conocarpus lancifolius, common name Damas tree.
Its roots may become a big problem.

 

Thanks so much, Tyrlych. We'd have never come up with that on our own.