Not a cactus… but still sharp!

Finally… about a year after germination and several different IDs later, my Euphorbia milii has decided to bloom.  It is still very small, only 4 inches tall in a tiny bonsai pot with a few small succulents (Schizobasis intricata, Sedum morganianum, and another E. milii to be specific).  I was under the impression that this plant would bloom in pairs, i.e. 2 blooms or 4 blooms and so on.  Mine either didn’t read the rulebook or is a little special.  Either way, it has decided to reward my year of neglect/diligence (depending on how you look at it) with a single colorful flower.