Lyophyllum fumosum (species of mushroom)
A specific species of mushroom; the name is typically written in katakana.
Senbonshimeji is a type of edible mushroom.
Katakana spelling is common for this mushroom name; usually written in kana.
Kanji spelling is rare; the word is usually written in kana.
The name literally means 'thousand-bundle shimeji', referring to its clustered growth habit. The exact derivation is uncertain.