At first I thought military, but lean more civilian flower button. It's not a thistle or tudor rose, and there does not appear to be room for having text going in a circle which is what we usually see. So to be military it would be an odd design having a normal looking flower, and it's marking would likely be a banner running through the center... which I can strangely make a small case for on the left side of the rose... but even if that was the case it's nothing that is familiar to me. It's quite a tease being a starburst, but I have seen other civilian buttons using that pattern.