Gloeophyllum sepiarium

November 28, 2022

Good evening, friends,
This week’s mushroom is the conifer mazegill (Gloeophyllum sepiarium). The latin is a little intimidating but I’ve heard it pronounced “Glee-o-phylum”. I found these mushrooms on 11/1/2022, but took some more pictures of them today and not much in their appearance has changed. While I found these mushrooms growing from a dead hemlock, you can often find them growing on benches and picnic tables. Keep your eyes peeled as they may soon be coming to a park near you.

Fun Facts
Do you know what a sepia is? Because I didn’t. Firstly, it’s a reddish brown color, so sepiarium just means sepia-colored. However, the color sepia – which I’d call a distinguished tan – is derived from the ink of a cuttlefish. Back in the day (the Greco-Roman days) folks figured out how to extract the ink from the ink-sac of the common cuttlefish (Sepia officinalis) and used the ink to draw and write. Leonardo da Vinci has some prints made from sepia ink and the practice of sketching with this ink carried through into the 1800’s.

Circling back to the mushroom, it is considered inedible due to its rubbery texture. However, extracts of this mushroom displayed anti-carcinogenic properties by reducing tumor growth by up to 80% in that often sited Ohtsuka et al.,1973 study. The top of the mushroom is mostly orange when young, and also a touch hairy on top, before it ages and turns darker around the point of attachment on the wood. The margin (outer edge) typically stays orange even as the mushroom ages.

G. sepiarium is saprobic on conifers (aka evergreens or “softwood”) and is seldom found on hardwoods. G. sepiarium is a “brown rot” fungus which means it digests parts of the wood that most fungi avoid – only approximately 10% of saprobic fungi create a brown rot. The brown rotters digest the cellulose and hemicellulose in the plant cell walls (big words, sure, but just think of them as the bricks that make up plant cell walls). The more common “white rot” fungi will consume those two substances but focus most of their efforts on the third component of the cell walls, the lignin (the mortar for the bricks if we stick with the analogy). One characteristic of brown rot fungi is that they decay wood in a chalky, brown, cubic pattern like you see at the base of the log these mushrooms were growing on:

The mushrooms pop up summer through fall in North America, Europe, and Asia. Since they can grow from treated wood they’re liable to pop up wherever and have been found in Africa and Australia – the opposite side of the equator from their native range. One last distinct feature is that unlike most polypores which have pores, these mushrooms have gills from which they release their white spores – similar to Daedaleopsis confragosa.

And here comes December, another calendar year just about in the books,

1)  Kuo, M. (2010, February). Gloeophyllum sepiarium. Retrieved from Web Site: