Day 237: While exploring a forgotten but close-by corner of the forest last year, I stumbled across something which looked for all the world like a quart or two of well-chewed pink bubblegum wads massed on a decaying log. I had never seen anything like it, so I documented it with photos from various angles and referred them out to one of Washington's pre-eminent botanists. Although he was unwilling to commit to anything further, he identified the substance as a slime mold and provided me with the email address of an expert in the field. It wasn't long before I had a reply and a name for my treasure: Lycogala epidendrum.
Lycogala epidendrum is one of the most recognizable of slime mold species, but it is not always pink. The fruiting bodies (aethelia) may range in colour from pale yellow to almost black at maturity, and indeed that was what Team Biota discovered when we visited the site recently. When opened, these aethelia appear to be filled with uniformly mushy goo, but under the microscope, this material is shown to contain thousands of spores and chain-like threads of sterile tissue (pseudocapillitia) which divide the chamber into irregular and often imperfect compartments. The term "fruiting bodies" is misleading. Unlike the apothecia of lichens, these structures do not develop like a bud on a rose or a pear on a pear-tree. Rather, they are a gathering-together of individual cells in response to a chemical signal, cells which otherwise would be living independently in the substrate. The chemical signal acts as their clarion call, communicating the message that it is time to reproduce. They become visible to our eyes only when they have formed the cooperating communities shown in this photo.
I suppose none of my friends will be surprised by this, but I couldn't resist the opportunity to do an experiment. In a corner of my living room, I have set up a pair of "moist chambers" (lidded Petri dishes) where I can monitor the growth of two samples. If I should disappear under mysterious circumstances, Lycogala should be considered the primary "substance of interest."
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