Panicum Texanum vs panic grass

Panicum Texanum and panic grass both are nouns.

Word	Noun	Adjective	Verb	Adverb
Panicum Texanum	Yes	No	No	No
panic grass	Yes	No	No	No

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

Panicum Texanum (noun)	panic grass (noun)
annual weedy grass used for hay	any grass of the genus Panicum; grown for grain and fodder