Never seen it before. Looks likeI recently discovered a sort of green jelly/slime growing on a concrete path and foundations here, and a bit of digging has revealed this to be a plus, I think. I'm going to keep an eye out to see if the chickens eat it, in wet or desiccated (brown crust) form. Maybe you have some too and can contribute to the topic.

Are you sure it isn’t solely Welch/British?.
Maybe it doesn’t grow here because there is way too much nitrogen (NOx) deposits in our country for this strange looking species.