Oops! forgot to insert the photo, sorry! : ) I'm hearing Maidenhair spleenwort, anybody agree?
As for an amateurish description, it is like a ground cover, not more than 8 inches or so off the ground. I've seen some ferns, this wasn't a very large fern, maybe leaves (fronds) 6 - 9 inches in length.
A lot of community highway departments plant Crown Vetch for erosion control. It's not a plant you would want to put in your yard. Very, very invasive and hard to get rid of once it gets a hold. I made that mistake once. It gets a pink, clover-like flower and is taller than the one in your picture. I'm not familiar with American Vetch.