Is this Purple Archangel
Sure looks like it, but it would be helpful to have a closer shot of the flower.
If you are thinking of eating it I'd bring some by the cooperative extension office just to be sure.
You got the extension office right here! It is red dead nettle, (lamium pupurium) a spring weed. It disappears as soon as the weather heats up.
I have never heard of purple archangel, but it could be a common name. It is a very common weed here in MO, but not worrisome, because it only appears for a short time. There are also some cultivated varieties that are more persistent.