"Make everything as simple as possible, but not simpler" ~ Albert Einstein, originally uploaded by Abby Lanes.
These flowers are the are the "Summer Snowflake" or Loddon Lily (Leucojum aestivum)
Here's the wikipedia link if you want more information. Apparently they don't care that it's winter in California.
I found them under a tree at Descanso Gardens, in La Canada / Flintridge, California.