Answer: I think what you have is Viola Tri-Color, commonly called Johnny-Jump Ups. Johnny-Jump-Ups come in many cultivated colors, but the basic wild form of this endearing little viola is not anything that needs improving. 'Helen Mount' is essentially the traditional or wild johnny-jump-up; ornate little faces painted on a single flower in purple, lavender, yellow, & white.
They pop up in unexpected places from years of self-seeding, not usually as aggressive, but retiringly, restrainedly, & humbly reliable for March.
Although they may prefer moist well-draining soil in a cool semi-shaded location, there is quite a patch of them in my garden that appeared practically in a packed-earth path in full afternoon sun. They're simply very adaptable & they do try to colonize areas that the weeds haven't gotten to first. Because they are so small, they are easily shoved aside by larger plants, so often have to settle for jumping up in places bigger plants avoid.
Enjoy your garden!
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