100 More Species #81: Lawnmower's mushroom

[urbpan]

Lawnmower's mushroom Panaeolus foenisecii

So called because most people encounter it seconds before they push a gas-powered rotating blade over it, the lawnmower's mushroom also goes by archaic common names like "haymaker's mushroom." It's one of the very few little brown mushrooms ("LBM"s) that has any common name at all. Paper field guides and some websites warn against allowing toddlers to gobble them from the lawn (a good guideline in general--I always advise against eating uncooked wild mushrooms) on account of small amounts of psilocybin possibly contained within. The Audubon Mushroom ID app lists them as edible but agrees to the possibility of some hallucinogen content. Wikipedia (the modern encyclopedia of record?) dismisses all this, attributing the oft-repeated "psilocybin in Panaeolus" myth to misindentifications and mistakenly lumping in unrelated but similar mushrooms found in similar habitats.



*Mushroom nerd sidebar:

I have found lawnmower's mushroom before at both Drumlin Farm and Franklin Park Zoo, and both times the mushrooms were bigger by half than these in my yard. I didn't think they could possibly be the same species, so I took a number of spore prints which all came out purple brown to purple black. I used several keys from Arora's "Mushrooms Demystified" and they all landed on P. foenisecii. The only field marking that didn't square out was whether the cap was "viscid" or not. Viscid means "slimy or sticky, especially when wet." These were quite dry until it rained again and the tops became kind of slippery. I reasoned that slippery is a condition of the cap itself, while viscidity implies a sticky or slippery substance on the cap, like a mucus, protein, or lipid.