Yes, There is an 'R' in the Month

Oyster mushrooms (Pleurotus ostreatus) growing on an almost dead horse-chestnut tree.

They seem to have experienced a dry/warm period that has hardened the outside of their caps, followed by a growth spurt that has cracked their caps. The result is a zebra-like camouflage.

Their undersides / gills can be seen in the 'Extra'.