The Carlisle Mosquito Online

Friday, March 18, 2005


Common Split Gill Mushroom

Readers of this column may have gathered that I am a fungiphile. I think the correct term is "mycophile" but I resist that label because of a text describing mycophiles as people who "grub in the earth like pigs in search of these detestable morsels" unlike "clean-living mycophobes who disdain foul-tasting fungi." Besides, I am the kind of fungiphile that is equally interested in edible and inedible species; (some inedible mushrooms, like today's common split gill, live very interesting lives); and in addition, the word "fungiphile" flows more freely from the tongue. Little treasures like the split gill help us fungiphiles get through the winter.

Name: The common split gill mushroom is Schizophyllum commune. Mushrooms are classified largely on the basis of their spore-producing structures. The split gill is unique in having longitudinally split gills. It is not very closely related to other gilled mushrooms so it is a member of a small family, the Schizophyllaceae, along with only ten other genera, one of which, the crimped gill mushroom (Trogia crispa) is quite common in this area.

When and where found: The common split gill can be found year-round and it is very widespread. It is one of the most widely distributed mushrooms in the world. It has been found on all continents but Antarctica where there are no trees for it to grow on. I found a cluster of it recently on some dead twigs at the Foss Farm. I have also found it in the Towle Woods, at Great Brook Farm State Park, and in my backyard. I found its close relation, the crimped gill mushroom, last fall in the Great Meadows Wildlife Refuge. Work done by John Raper and colleagues at Harvard in the 1950s to 1970s confirmed that split gill samples collected worldwide were in fact members of a single species. These scientists were able to show that the common split gill has 28,000 different mating types, or sexes. Eat your heart out, Dr. Ruth. There is a brief description of the genetics and mating compatibility on Tom Volk's mycology web site at the University of Wisconsin (the link is below in the references).

Distinguishing Characteristics: The common split gill mushroom is whitish, fan-shaped, hairy, and fairly small — less than an inch and a half across the cap. If you find one split gill mushroom, you will probably find a dozen or more since it tends to grow in groups. It does not really have a stalk, and the gills radiate from the point of attachment to the dead wood it is growing on. The gills are white or gray and split into two parallel plates. The plates roll up in dry weather to protect the spore-bearing surface. The gills can open and close over and over again as the weather changes — a useful feature in climates with sporadic rains. A lab specimen sealed in a tube in 1911 was able to unroll its plates and shed spores when moistened after 50 years.

References: Tom Volk's Fungi at fungi/feb2000.html (Tom is a professor of mycology and maintains a very useful and interesting web site — fungiphiles might want to bookmark it); David Arora, Mushrooms Demystified (this is a field guide with a sense of humor and while written largely for the western states, the new edition has been revised to include more of what we find here); Gary H. Lincoff, National Audubon Society Field Guide to Mushrooms.

Submissions for the Biodiversity Corner are encouraged from everyone. Have you seen something interesting? Draw its picture, take its photo, write its story. The only requirements are that the subject exists in the wild and was seen in Carlisle. Send your ideas to Kay Fairweather at 392 School Street, Carlisle MA 01741 or to

2005 The Carlisle Mosquito