Violets? Yawn. I wish I had violets.
Try dealing with a few dozen square meters of creeping buttercup. My god. I’ve resorted to seeding my lawn with chewed-up wild strawberries to compete.
Rhizome war!
Wild onions (actually triquetrous leek) are the weed enemy in my garden - the plant reproduces by seed and division - hundreds of tiny bulbils that bud off the main one - it’s impossible to get them all out and they just keep regrowing.
Maybe I’m stirring up trouble for nothing, but I’m a little suspicious of people who wage all-out war on dandelions, complete with hazardous chemicals that run off into the water supply (hey, I drink that water too!) and then go to the nursery and pay a premium to buy plants with yellow flowers!
Dandelions:
- are hardy
- require little to no maintenance or supplemental watering
- are edible
- bloom with a clear, bright, pretty lemon-yellow color
- re-bloom reliably
- offer interesting seedheads
- come back year after year
I can’t think offhand of any other plant that fits every single last one of those requirements.
Yes. Here’s and example of what the leaves look like on undisturbed dandelions.
In the lawn they’re much flatter.
BTW is the “wild lettuce” that has been mentioned the same as what we call “cat’s ear”?
That’s the Hawkweed (I thought so). Wild lettuce is a common roadside weed - tall with big paddle-shaped leaves that stick out all over like jug ears.
purplehorseshoe, the only difference between a weed and a beloved plant is whether it’s wanted or not. I don’t want dandelions, hence they are weeds. I do want violas, so they are beloved plants. 
You might enjoy our last spring’s rant on the subject. (Warning: linked thread extinct in April 2009, do not resuscitate.)
I want to have purplehorseshoe for a neighbor.