In his musings on the nature of mushrooms and fungi, Ken Thompson investigates the vegan attitude to mushrooms.
“Vegans advocate a plant-based diet, but many vegan recipes contain mushrooms. In the vegan universe, mushrooms (and presumably fungi in general) seem to be honorary plants, even though they are more closely related to you and me than to cabbages and beans. This makes perfect sense; fungi may be unrelated to plants, but all the arguments for a plant-based diet apply equally to fungi. Not only that, if fungi were off the menu, avoiding the yeast in beer and wine could make life very dull.”