Catathelasma ventricosum (species of mushroom)
A specific mushroom species; the name is typically written in katakana as is common for biological names.
Momitake is a type of edible mushroom.
Katakana spelling is common for mushroom names; usually written in kana.
Kanji spelling exists but is rarely used; the word is usually written in kana.
The name likely derives from 樅 (もみ, fir tree) and 茸 (たけ, mushroom), referring to its habitat or appearance, but the exact origin is uncertain.