Corroded Copper-Alloy Coin/Token From Archaeological Site

Button is a possibility, but there is no trace of a shank or eye left on the object. Since this came from the site of a 17th-century Franciscan mission I was wondering whether it might be a religious token.

I'm thinking a button too, because of the central blob on the back. I don't see any obviously religious symbolism on it.

Well, the image of the back is a bit misleading - there really isn't a blob or elevated area on it. Thickness is 1-1.1 mm throughout. That said, given the state of corrosion, any shank or wire-loop attachment could well have broken/eroded off.

Thanks for all the input so far - if anyone can make something of that branch motif on the front, I'd be eager to learn about it. In the meantime I'll fire up the coffee-maker and start looking into colonial-era copper-alloy flat buttons....