Pluteus cervinus
Long ago, mushrooms were the precise example people used to define brevity. George Washington considered mushrooms to be a derogatory example of a temporary enterprise--something not to be trusted. And he wasn’t alone. Thomas Jefferson despised the so-called “mushroom banks” that sprang up opportunistically in the early 1800s, issuing bills that might be worthless tomorrow.
For Washington, nothing of quality or reliability would follow the example of the mushroom. Of an English threshing machine he considered acquiring for his farm in 1793, it must be reliable and simple, America’s first president begged, “ ... for if there is any thing complex in the machinery it will be no longer in use than a mushroom is in existance [sic],”
Not all mushrooms are so sadly ephemeral. Yet some truly define the  reputation. In Illinois, the brief life of mushrooms included in the scientific genus Pluteus, including the common and widespread Pluteus cervinus, is remarkably instant. One day a graceful, gilled mushroom pops out from a rotted log. The next day--all is rotten.