At least I think they're seed pods. I noticed these strange looking things growing all over the surface of my mulch.
They look like tiny black cupcake papers containing small black disk shaped seeds. The cupcake things are firmly attached to pieces of mulch. Nearby plants include a Euphorbia Milli, Pregnant Onion, Day Lilly, and Bromeliad. I've tried some online research on seed pods for each of these plants but haven't come up with any definitive answers. If I had to guess I'd say they came from Euphorbia. I've included photos. Can anyone ID them?