Rhizopus; bread mold fungus
A genus of saprobic fungi commonly known as bread mold; the Japanese name literally means 'spiderweb mold'.
Rhizopus often grows on bread and fruit.
One species of this Rhizopus is related to the koji mold used in sake brewing.
麹黴 (Aspergillus oryzae) is a beneficial mold used in fermentation, while クモノスカビ (Rhizopus) is often a spoilage mold, though some species are used in food production.
Katakana spelling is standard for this fungus name; usually written in kana.
Kanji spelling is rare and mainly found in older or specialized texts; the word is usually written in kana.
From 蜘蛛の巣 (くものす, 'spider web') + 黴 (かび, 'mold'), referring to the web-like appearance of the mold's mycelium.