I've got several patches of this fungus growing in my mulch. It grows in roughly a circular patch, and produces these growths above the surface.

Fruiting Body of Fungus

The effected area binds together into a disk, and when broken and flipped it reveals a white mossy underside to the patch.


  1. What is this stuff? Is it dangerous?
  2. How do I remove it without spreading it?

I've noticed a much larger growth in the neighbor's mulch. :(

Edit: A better picture was requested - Here is a zoom and crop of some of the mature fruiting bodies:

Zoom and Crop of fruiting fungus

  • Try for a better picture? Mushroom identification is hard enough... perhaps inky-caps, but it's difficult to tell at that angle. Inky-caps would certainly fit the environment mushroomexpert.com/coprinoid.html
    – Ecnerwal
    Commented Jul 29, 2015 at 1:41
  • Egg cup fungus? Looks like cups with little eggs inside? Need a closer picture with 1-3 of the fruiting bodies in it. Commented Jul 29, 2015 at 1:49
  • I think it might be egg cup- i posted a zoom and crop of the first picture. Commented Jul 29, 2015 at 1:59
  • Your profile says you're in Cincinnati, Ohio. Is that where these mushrooms were found?
    – Niall C.
    Commented Jul 29, 2015 at 3:06
  • Yes, in Cincinnati. Commented Jul 29, 2015 at 3:19

1 Answer 1


This is a member of the Nidulariaceae / birds nest fungi, the exact variety would need better photos and possibly a microscope, but I can still answer your other questions:

  • No, they are not dangerous. Inedible, but they don't damage your garden. They do what they do best, which is eating the decomposing wood from your mulch.
  • The white "felted" disc underneath is the actual fungus, the mycelium, the cups with the lentil-shaped peridioles are only the fruiting bodies. Think of the mycelium as the apple tree and the fruiting bodies (which we often call "mushroom") as the apples which contain the seeds (spores).
  • For removal you can simply lift the mycelium, preferably before the cups open. Another option would be to keep your mulch very dry (probably not feasible). But I wonder why - if you spread mulch it's normal for it to break down and fungi are a natural part of this process. If they appear, your mulch has already started to decompose. In this case you would have to regularly (e.g. annually) excange the "old" mulch for fresh mulch, but apart from esthetical reasons (and beauty is in the eye of the beholder, I personally love to see nature do it's thing where possible) I see no necessity to do so, especially if your neighbour has "a larger patch", as you wrote, meaning you will constantly get new spores into your mulch.
  • This particular mulch is not yet a year old, but we've had an unreasonably rainy June and July and this is on the north side of the house where the mulch probably stays pretty shaded. The fruiting bodies are less than a quarter inch in diameter, and I'm pretty confident you're correct that they are birds nest fungi. Thanks for the info. Commented Jul 29, 2015 at 12:18
  • @tom.dietrich - You are welcome! So what's it going to be? Attempt at removal or live and let live?
    – Stephie
    Commented Jul 29, 2015 at 13:32
  • Don't want the spores on my concrete and brick, so I'm going to break it up where it might splash to there, leave it be where it poses no such threat. Commented Jul 29, 2015 at 13:34
  • @tom.dietrich probably won't do anything on concrete etc - the spores simply won't find anything to nurture them. I don't think they are dangerous, it's those Aspergillus etc. inside that make you sick. There are millions of spores outdoor, typically benign.
    – Stephie
    Commented Jul 29, 2015 at 14:44
  • Been waiting for a mushroom/fungus question to see what you'd say, Stephie!...whole 'nuther beast, fungi!! Spores and fungi will NOT hurt your concrete and brick, Tom!! These guys thrive on non-decomposed wood...etc. and never become a problem. To try to do anything will be a waste of time. These are parts of an organism responsible for decomposition that you can actually see! Lots more just like them just not visible. All a part of a cycle that is critical for a healthy, thriving environment regenerating itself...
    – stormy
    Commented Jul 29, 2015 at 19:24

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