The fall is typically mushrooms’ time to shine. It is a time of year when my lawn is typically bursting with a variety of mushroom species, and I see a whole palette of colors on my forest walks (my favorites: the lovely purple Viscid Violet Cort and the bright orange edible Chicken of the Woods). But last summer’s drought made for an underwhelming fall mushroom season. 

I figured I’d be out of luck with finding interesting new mushrooms until next fall, since I rarely notice mushrooms in the winter. During a walk this past weekend, however, I encountered the largest, perkiest bunch of oyster mushrooms I’ve ever seen. In January! With temperatures mid-day barely above freezing, and nighttime temperatures well below. My first thought was that these had sprouted weeks or months earlier and had somehow frozen in this state. However, upon further research, it turns out that I had found Pleurotus ostreatus, a species of oyster mushroom that most typically fruits during cold weather (November through April). 

The gills of oyster mushrooms are widely spaced and are interspersed with many shorter gills. The mushrooms themselves grow in shelf-like clusters and have a short, nearly absent stem covered in tiny hairs. There are a couple other closely related oyster mushroom species that you could confuse this one with, but P. pulmonarius appears between late April and September, so time of fruiting can help differentiate these two, and P. populinus is only found on poplars, cottonwood and quaking aspen, while P. ostreatus can be found on a variety of hardwoods, and occasionally conifers. 

So apparently my lack of mushroom observations in previous winters could simply have been due to lack fo looking.