February 28, 2022
Good evening, friends,
This week’s mushroom is Neofavolus alveolaris, formerly Polyporus alveolaris, and commonly known as the hexagonal-pored polypore. This mushroom was found on 2/17/2022 after the snow melted up in Manitou. I’ve found this mushroom in Inwood Hills park so it’s in Manhattan as well. Before we go any further, I don’t want to mislead you because, no, not all the pores are hexagonal. A more creative common name seems to be in order – perhaps the “honeycomb polypore”?
N. alveolaris contains a unique anti-fungal and anti-bacterial compound appropriately named alveolarin (reference 3). Producing this compound in the fruiting body allows it to resist predation from other fungi and bacteria so the mushrooms can keep releasing spores. It’s possible alveolarin is produced in the mycelium of the fungus as well to help them keep other white rot fungi from inhabiting and consuming the same wood.
The mushroom is noted as edible when young but it becomes quite rubbery and tough with age. It’s also noted for a bland taste and on wikipedia is helpfully listed as “edible or inedible”. Dealer’s choice.
These mushrooms typically have an orange cap when fresh. The mushrooms photographed have a white cap – with orange just on the margin of the cap – as the color fades with age. It’s possible these specimens are close to a year old since they typically fruit in the spring. The previously discussed compound alveolarin could be one reason the fruiting bodies resist rot and persist through the varying seasons.
One last note is that this tree was standing vertically when the mushrooms grew and it fell sometime before I found them. Geotropism is the growth and orientation of organisms with respect to the force of gravity. If these mushrooms grew when the tree was on the ground they would grow so the caps are parallel to the ground – and the spores are being pulled out by gravity – as opposed to their current perpendicular orientation to the ground.
N. alveolaris is saprobic on hardwoods, like the oak it’s growing on here, and causes a white rot of the heartwood. It’s noted to prefer shagbark hickory (Carya ovata) as well. It is found across North America, Europe, Asia, and Australia. It fruits spring through fall and, as mentioned, the hardy caps can be found year-round. As seen in the photo above, the mushroom has decurrent pores which means they aren’t just under the cap but they run down the stem of the mushroom as well. The featured mushrooms are on the larger end for the species as they usually range from 1-10 cm in size. Growth can vary from one solitary mushroom up to a flush of several scattered across a branch/log.
1) Kuo, M. (2015, March). Neofavolus alveolaris. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/neofavolus_alveolaris.html