Fraxinus texensis vs ash tree

Fraxinus texensis and ash tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fraxinus texensis	Yes	No	No	No
ash tree	Yes	No	No	No

As nouns, ash tree is a hypernym of Fraxinus texensis; that is, ash tree is a word with a broader meaning than Fraxinus texensis:

Fraxinus texensis: low-growing ash of Texas
ash tree: any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus

Other hypernyms of Fraxinus texensis include ash.

Fraxinus texensis (noun)	ash tree (noun)
low-growing ash of Texas	any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus