Celebrate (white)
In Germany, Mother's day is in mid May, the time when usually also everything's abloom in lilacs in our parts. My mother loves the white kind best and also has strictly forbidden to get her commercial flowers for the occasion. Since her birthday is on May 25th, mostly about a week later, she usually gets lots of white lilac cut from the bushes of family and friends, and white lilac has always represented "celebrate mum" for me. ^^