urn fungus vs Urnula craterium

urn fungus and Urnula craterium both are nouns.

Word	Noun	Adjective	Verb	Adverb
urn fungus	Yes	No	No	No
Urnula craterium	Yes	No	No	No

As nouns, urn fungus and Urnula craterium are synonyms defined as:

urn fungus and Urnula craterium: an urn-shaped discomycete with a nearly black interior

urn fungus (noun)	Urnula craterium (noun)
an urn-shaped discomycete with a nearly black interior	an urn-shaped discomycete with a nearly black interior