Volvaria bombycina vs fungus

Volvaria bombycina and fungus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Volvaria bombycina	Yes	No	No	No
fungus	Yes	No	No	No

As nouns, fungus is a hypernym of Volvaria bombycina; that is, fungus is a word with a broader meaning than Volvaria bombycina:

Volvaria bombycina: a parasite on various trees
fungus: an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia

Volvaria bombycina (noun)	fungus (noun)
a parasite on various trees	an organism of the kingdom Fungi lacking chlorophyll and feeding on organic matter; ranging from unicellular or multicellular organisms to spore-bearing syncytia