A species of poroid fungus that decomposes hardwood stumps and logs. It is inedible.

Contained within these unassuming shelf fungi, there could be a staggering 17,550 different combinations to choose from. Why any organism would need so much sexual variation remains an open question, but study author and University of Oslo geneticist David Peris suspects it has to do with the mushrooms’ sessile lifestyle: having to be different at two different gene regions makes it less likely for spores released from the same mushroom to successfully combine, thus lowering the odds of inbreeding.

Also, having so many variants to choose from makes it more likely any given neighbors will be sexually compatible which could help the species survive.