First picture is of the F1 Viola striata X walteri just starting to open a few blooms. I've had two F1 plants for over 10 years and they make a nice ground covering mat about a yard across each year. I trim the dead off in winter or early Spring and they're good to go for another year.
They are almost completely sterile but do make occasional seedlings that vary in color and growth habit. The next two pictures are of two that I'm keeping an eye on as possible "improvements". This first one has bunched up nicely and has more of the upright habit and white flowers of Viola striata. It's also shown a pretty reliable tendency to repeat in the Fall.