I has got three pots of it at my friend's nursery, specialized in "alpines". A very pretty tiny violet.

--
Denis

Here is a link that might be useful: My friend Gaby Servat's Nursery

Well, I've got one this fall. Have to wait until spring/bloom time to see if it's "pure" or a var. :-)
There seems to be 5 var. of that viola in Masashi Igari's book:
var. fibrillosa
var. semilunaris
var. subaequiloba
var. yakushimana

Denis: 3 of them ??? Are you thinking about a green bed so as to accomodate Brigitte TheHedge ? ;o)

I have var. fibrillosa.
I got it years ago by mistake - it came in a pot of other stuff from RHS Rosemoor.
It is hardy and self-seeds well, though individual plants can also last many years.
Like many small violets, you need to get close to appreciate the flowers; otherwise it might just seem a bit weedy.