I'm not sure I have this identified quite correctly. The vetches are really tricky, and there are quite a few of them. But of the four that I've found in my field, the white one is least often found. Even though it's white, I'm pretty sure it's not Canadian Milk Vetch, Astragalus canadensis.
I used to think that it was just a color variation of this Hairy Vetch, Vicia villosa, or the Cow Vetch, Vicia cracca, which is really similar, but all purple. But I'm not sure if it's really a different plant.
Here are some buds. I like how they curl
The leaves are rounder than the others, too. All three of these that I've just mentioned are good cover crops (they are legumes, so they put nitrogen back into the soil), and they are good food for cows. But they are not good at all for humans, and other mammals with one stomach compartment, to eat. They contain cyanide. A couple of seeds won't kill you, but a large quantity could. In other words.... these are not a wild edible that you should gather!
|See Leguminoseae, OK... Pea Family|