 The first report of a gilled mushroom fruiting underwater is "Psathyrella aquatica".The genus name "Psathyrella" is a diminutive form of "Psathyra", derived from the Greek word meaning "friable", psathuros (ψαθυρος).The type species of "Psathyrella" is "Psathyrella gracilis", which is now known as "Psathyrella corrugis".