Mom has that exact same one all over her lawn. ;-) She planted them about 25 years ago and they've naturalized. She thought she remembered them just being called woodland violets, but she wasn't sure. I haven't been able to positively ID it either ~ sorry, that's all I have. I hope you do get a better, more definitive answer!
Your welcome! :-) I should mention that they're incredibly tough and make good border plants. Mom isn't really a gardener and just wanted to line her walkway with something that wouldn't take much care. If she would have kept them in line from the beginning, I'm sure they wouldn't have spread so much. But I think they look cute at this time of year, all green in little mounds with the lavender flowers ~ even in Mom's lawn they're cute! ;-) I transplanted some into the border of my front flower beds three years ago and they're thriving despite much abuse.
I wonder if the wind or the birds scatter the seeds. I have them coming up in places far away from the plants. They do get very thick too. Some how I even got a few that have white blooms. Don't have any idea where they came from. Nice to see the little blooms in the spring though.
Ah, the sweet violet! They grow along the marshy woodland areas up here in Southcentral Alaska. We call our variety "marsh violets", and they are more of a lilac or lavender colored bloom. I've transplanted several of them into my shadier portions of my lawn, and they always fare well. For those of you interested in the way the transport seed, I'm going to post a pic on a new thread.
As for whether it is a weed or not, remember,Tim, that a weed is defined as any plant that grows where you don't want it to!...WZ
Ok, definitely a violet - I am not even going to hazard a guess as too the latin, as there are enough species of violet to keep me confused! (and I don't have my book).
As far as the seeds - violets have a seed pod that splits open when fully ripe and broadcasts the seed far and wide. Also, the little beggars have fat little rhizhomes that produce new plants, so you can get a healthy patch of them in no time. I love them - here in NH my lawn is full of them, white and blue large flowered and the tiny white sweet violets.
Try either Viola septentrionalis (Northern Blue Violet) or Viola sororai, syn. viola papilionacea (wolly blue violet) I love them too. Brought them here to NC from CT and they grow well, sun or shade. They are one of my favorites.