Look also under Camellia nitidissima. Supposedly one was being grown against a wall in Tacoma awhile back. Don't know how long this planting was successful. I've never seen this species being overwintered outdoors here myself.

Looks like a tea plant (Camellia sinensis) with yellow petals and bigger leaves, not a stunner by any means. Try Nuccio's, in California--they have supplied it in the past. Cistus nursery, near Portland has also sold it.