Q.What is this and how do I get rid of it?
This “stuff” forms a solid covering over everything. I first noticed it in my Asparagus bed. It has spread to my flower beds. I have tried lime, “moss out” and weeding. It comes up in sheets. I have buckets of it because I am afraid to put it in my mulch pile. I have been battling this for 3 years and it is winning.

What is that? It kind of looks like a cactus...or maybe a slime mold. What I like to do, when I find something that needs identified, instead of spending hours poring over ID sites, is to take my mystery plant to the county extension service. They usually can identify it. This link will help you find the nearest office:
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm
Maybe someone else will have a better answer to what this is...got me stumped.