Tilletia caries vs smut fungus

Tilletia caries and smut fungus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tilletia caries	Yes	No	No	No
smut fungus	Yes	No	No	No

As nouns, smut fungus is a hypernym of Tilletia caries; that is, smut fungus is a word with a broader meaning than Tilletia caries:

Tilletia caries: fungus that destroys kernels of wheat by replacing them with greasy masses of smelly spores
smut fungus: any fungus of the order Ustilaginales

Other hypernyms of Tilletia caries include smut.

Tilletia caries (noun)	smut fungus (noun)
fungus that destroys kernels of wheat by replacing them with greasy masses of smelly spores	any fungus of the order Ustilaginales