Spotting

Description:

Really tall skinny tree growing in my backyard. It only has a few branches but the stalk is at least 15 feet tall and grew dramatically this spring. It has small clusters of leaves that look like they are growing out of the center of a 4-petal flower. There are flowers growing in the leaf clusters that look like broccoli.

Habitat:

Overgrown area on side of hill with lots of pricker bushes around it.

Notes:

I'd love some suggestions on what this might be. It's a very cool looking plant! We've been calling it the broccoli tree.