Difficult to tell. They are difficult to tell apart until the buds start forming, spikes are usually a bit more rounded at the tip and if you feel them gently you can feel the buds inside as they start to develop.
The way the top is opening on that I would guess it's a growth, but it could go either way.
---------- Post added at 12:52 PM ---------- Previous post was at 12:09 PM ----------
I just found the second thread on this, and I've merged the two. Best to just post once so that all the answers are together.