grass bacillus vs bacillus

grass bacillus and bacillus both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass bacillus	Yes	No	No	No
bacillus	Yes	No	No	No

As nouns, bacillus is a hypernym of grass bacillus; that is, bacillus is a word with a broader meaning than grass bacillus:

grass bacillus: a species of bacillus found in soil and decomposing organic matter; some strains produce antibiotics
bacillus: aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil

Other hypernyms of grass bacillus include B.

grass bacillus (noun)	bacillus (noun)
a species of bacillus found in soil and decomposing organic matter; some strains produce antibiotics	aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil