kniphofia said:It's possible your V tricolor did see around, they are quite variable and sometime appear in white or yellow forms.
That's what I originally thought, but there are zero other violas in this part of the yard. All of my seeds stayed in the garden beds I put them, about fifty feet away. The chances that one seed flew across the garden and just happened to be the one seed that was a mutated version (none of the hundreds of other seedlings are white) seems highly unlikely...