What is the name of the plant with large purple blooms? (see details)?

I'd like to know the name of the plant with the following description. If you can provide a few possibilities for the identity of this plant, I can do an image search to confirm.


The plant is currently (January) in bloom in northern California. I've seen this plant in varying sizes, from a 5-foot bush to a 15-foot tree. It's most distinguishing characteristic is softball-sized flowers. The petals are a dark purple at the base, shifting to white at the tips.

What is the name of the plant with large purple blooms? (see details)?
im going to say a hydrangea.several varieties of these around, but they probably are blooming in ca now. if its blooming in that shape, thats most likely it.
Reply:It may be a hibiscus... do you have a pic?
Reply:It just might be a lilac. I've seen them in Big Bear outside of Los Angeles, but not sure of the time of year. Spring comes early in California and lilac is a spring bloomer.