I was in the backyard tidying up after my dog when I noticed a tiny orange mushroom growing out of the moss in the lawn. It is a fragile thing, about an inch long. The cap has a slightly darker indentation on top. Even the stem is orange, and the gills look like the fan-vaulted ceiling of a miniature cathedral and extend a short distance down the stem. I am curious to know what it is.
I confirmed with local mushroom experts that this is Rickenella fibula. It is fairly common in the Pacific Northwest, but seldom noticed, so good spotting! The technical description of gills that extend down the stem would be “decurrent, slightly traveling down the stipe.” Here is general information about this mushroom from Michael Kuo’s Mushroom Expert site. He mentions that it may have a mutualistic relationship with moss, and that is discussed further on the Forest Floor Narrative blog:
“Most species that occur with moss are saprobes that share similar niche requirements with the moss. That is, many of these organisms can only exist in a certain range of temperature, moisture, pH, and nutrient content of the substrate. Much of the time, they don’t directly interact. Moss loving fungi break down dead plant material that may leach and be absorbed into the plant, but these interactions are not considered mycorrhizal. Recent studies indicate that Rickenella fibula doesn’t just coexist with the moss it is found growing with. There is actually a direct interaction going on here.”