I learned about and became interested in mushroom knives when Smoky Mountain Knife Works introduced a one in their Rough Rider brand in early 2013. (RR1400) I had never heard of such a knife before then. (The Rough Rider Knife is the bottom one in the picture).

The Mushroom knife is a specialty knife used for harvesting mushrooms. Most often, the mushroom knife has a blade that looks like a small scythe or a type modified hawkbill blade which is used to cut the mushroom stalk. This allows the mushroom to be harvested without damaging the mycelium; an underground structure considered vital for the environment.