PIGSKIN

​The Deceptive "Pigskin":

Common Earthballs at the Glade

​Walking through the Glade Trust Nature Reserve this week, you might spot some peculiar, potato-like shapes nestled among the moss and leaf litter.

​These are Common Earthballs (Scleroderma citrinum), a fascinating, though often misunderstood, resident of our forest floor. While they might look like simple stones or potatoes at first glance, they play a complex role in our woodland ecosystem.

​Identifying the Earthball

​The photo above captures a group of Earthballs in various stages of life. Unlike the edible "Common Puffball" which is white and marshmallow-like inside, the Earthball is a tougher character.

• ​The Look: They have a thick, leathery skin (peridium) that is scaly and yellowish-brown, often earning them the nickname "Pigskin Poison Puffball."

• ​The Interior: If you were to see one cut open (or split naturally like the ones in the photo), you wouldn't find white flesh. Instead, the inside is a dark, purple-black mass of spores.

• ​The Split: As they mature, the thick skin ruptures irregularly to release these spores into the wind. Sometimes, as seen in the top-left of our photo, they can split in a way that mimics an Earthstar fungus, but the dark, dusty interior gives them away.

​Friends of the Forest (Mycorrhizal Partners)

​While they look like they are just sitting on the ground, these fungi are hard at work underground. Unlike fungi that simply eat dead wood, Common Earthballs are mycorrhizal.

​This means they have a symbiotic relationship with the trees around them—particularly our oaks, beeches, and birches. The fungal network (mycelium) wraps around the tree roots, helping the trees absorb water and vital minerals like phosphorus. In return, the trees feed the fungus with sugars produced from photosynthesis. They are literally the life support partners of our canopy!

​⚠️ A Note of Caution: Look but Don’t Eat

​It is crucial for all visitors to know that Common Earthballs are poisonous.

​They are frequently confused with edible puffballs, but eating an Earthball can cause severe gastric upset. The quickest way to tell them apart is the skin (Earthballs are thick and tough; Puffballs are thin and papery) and the interior (Earthballs are dark inside; fresh Puffballs are pure white).

​As always at the Glade Trust, we encourage a "look, don't touch" policy. These fungi are best admired as part of the scenery, doing their job to keep our trees healthy.

​Where to find them

​They love acid soil and are often found on mossy banks, near rotting stumps, or right at the base of living trees. Next time you are on the trail, see if you can spot these "forest potatoes"—but remember to give them plenty of space!

​Have you spotted these earthy spheres on your walk?

Let us know in the comments, and share your photos of the Glade's winter wildlife!