Urnula craterium vs urn fungus

Urnula craterium and urn fungus both are nouns.

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

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

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

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