It looks to me like heuchera villosa macrorhiza. The large, white blooms you described make me think it's a particular one called 'Autumn Bride'. Yours looks to be very healthy and happy.

This post was edited by flower-frenzy on Thu, Aug 21, 14 at 0:49

Thanks flower! Mine always look good. I really like this work horse plant.

Sherry

Coral bells are a favorite of mine and have several in the shade. I have a Palace Purple that gets full sun up to about 2:00 and is doing great. Are there any that can take all day full sun?

Most of the really dark leaved ones can take full sun. I have Midnight Ruffles, Obsidian, Blackout and Black Tafetta in full sun and they do fine. I have to keep up the watering, though. If I let them get too dry, some of the leaves will get brown and crispy.

Sun loving heuchera, name coral bells plant. My one of favorite plant.

I don't have that particular Heuchera (yet), but I do have a description for Heuchera 'Autumn Bride' -- 24” Tall. Fuzzy, large lime-green leaves in summer,
white “sprays” of flowers that bloom Sept-Oct. If yours stays green the whole year through, it sounds like it's this Heuchera. Good to know how well it does. I may have to get one this year.