Cow Vetch is also called Scrub Brush by native herbal practitioners around the parts where I live. It's called that in part because of the look of the flower, with all flowering bodies on one side mimicking the look of a scrub brush, but also apparently because a tea made from this plant will clear out your system.
I'm also finding online that the leaves are edible, as are young stems, and seed pods as well, all when cooked. They indicate that the leaves and young stems are used as a potherb. Looking into what is meant by potherb, it means anything used for culinary purposes from a use as a green like with spinach, to seasoning like Thyme or Rosemary.
It's also indicated as a Galactagogue which means that it is known to promote lactation.