Cornell Mushroom Blog

The Friday Afternoon Mycologist turns to tape in a sticky situation.

Some people put tape on their teeth, hoping to make them pearly white. Others rip tape from their skin, hoping to remove offending blackheads and dead skin cells. A world without tape would be like a world without fungi: a much less sticky place.

This is the true story of how I became the Friday Afternoon Mycologist.

The phone rang, and the caller identified himself as someone with official responsibility for controlling the passage of questionable substances across international borders. The unionized workers responsible for inspecting such items were refusing to inspect an automobile that was covered with mould. Was it safe?

Phone calls like this seem like obvious jokes, especially late in the afternoon. Could it be your old college roommate or that joker down the hall? Once — this is also true — I received a Friday afternoon call from someone claiming to work for ‘The X-Files,’ looking for a culture of mutant wheat rust to use the next day for a scene. I explained that wheat rust did not grow in agar culture, and suggested they should rewrite the script for scientific accuracy. When the program finally aired, Scully pulled a Petri dish from the refrigerator and, without making a slide, looked through her miracle-microscope, revealing that all plants in the San Bernadino Valley had been killed by the spores of an Agaricus mushroom the producers had bought at a grocery store.

The man with the mouldy car needed an answer fast. It was not a matter of the tax value of the mould or the car, just that law required that the car be inspected. The unionists being unwilling, he would enter the car himself. What should he do? I had a vision of him removing the entire seat and hauling it to my lab, and then me trying to flatten it so it could be stored in our herbarium. But instead, I told him:

1. Get some clear cellotape, not the ‘invisible’ present-wrapping kind, but the glassy clear kind.
2. Take a piece of tape 1-2 cm long. Press the sticky side of the tape firmly against the mould colony.
3. Gently place the tape on something clean, something that the tape can be easily removed from, like a credit card or a piece of plexiglass.
4. Bring it to me.

It was Friday afternoon, just after lunch, when he showed up. He had photos of the mouldy automobile. The car was an expensive model with leather seats. It had been enclosed in a shipping container in a warm, humid tropical country, then transported half way around the world to this much colder country, resulting in a lot of condensation and thus a lot of mould. Moulds like condensation. If we were to hold a mycological election, and the main campaign issue was dampness and mist, and moulds were the voters, it would be a landslide.

I took his tape samples and mounted each on a microscope slide, with a drop of 85% lactic acid mounting fluid underneath the tape, and a drop of the same on top, then a cover glass. When I looked through the microscope, here is what I saw:

Any mycologist worth his or her immersion oil would recognize this as an Aspergillus. It can cause some alarm, being the generic home of such horrors as A. fumigatus, a leading fungal killer of immunocompromised hospital patients, and A. flavus, source of the nastiest of all natural toxins, aflatoxin, the bane of turkeys everywhere. But the leather seats, the humidity, the shape of the spores all made a convincing story that this was actually the Aspergillus form of a Eurotium species. Eurotium grows on all kinds of things that get wet and then dry out but stay in a humid place… and it really likes leather. I once found it growing on the webbing of my old lacrosse stick in the less-than-ideal archival conditions of my basement. It is also the target of scorn and disgust from military personnel, who find it growing on their tents and leather boots when they participate in tropical adventures. BUT, it is not terribly dangerous, is not a pathogen, does not make many horrible toxins; at worst, it might lead to a lot of sneezing or some asthma.

My client was happy. The car could be released to its esteemed owner, who could decide for himself how to clean it up.

The moral of this story, however, is that you too can use tape to explore your world. House dust, that suspicious fuzz on the couch, mouldy gnomes, the mildewy haze on the garden plants. You need a microscope, of course. Or a friendly neighbourhood mycologist, who probably won’t mind if you knock on his or her door at about 2 o’clock on a lazy Friday afternoon.

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