The flowers of violets are an old fashioned treat. I remember having candied violets at summer teas as a child. I have since recreated them once or twice as an extra treat for friends. I also regularly add flowers to my salads, drinks and desserts, in the summer time. Not all flowers are edible, but the sweet violet or viola is.
The flowers of the violet, are pretty bland, but have a slightly sweet flavor reminiscent of their scent.
For other edible flowers check out the related link below.