On the the other side of my block there is a house where once someone planted a crocus or three. The crocus are happy and over the last twenty years I have watched them take over the lawn. They now ARE the lawn at least until the first mowing (which isn't all that early given the owner).

I did a bit of investigating a number of years ago and this is what they appear to be:
Crocus tommasinianus




I'm home today with something I got at school. A bunch of my colleagues were also sick so finding subs became not so easy. That is why this is a very long distance shot -- I took the picture out my kitchen window.