A tiny sharp point!

Debbi hasn't set any special theme for today's Tiny Tuesday challenge so I thought I'd blip this macro shot. Before you ask, no it's not some sort of vicious eye surgery instrument left over from my past life! But I did come across a lot of these this morning but in spite of taking great care I did manage to prick my finger on one of them (a very minor injury, no worries about that).

I suspect someone will guess what it is (maybe I've given too many clues!) but if not I'll give the answer tomorrow.