Quercus nuttalli vs oak

Quercus nuttalli and oak both are nouns.

Word	Noun	Adjective	Verb	Adverb
Quercus nuttalli	Yes	No	No	No
oak	Yes	No	No	No

As nouns, oak is a hypernym of Quercus nuttalli; that is, oak is a word with a broader meaning than Quercus nuttalli:

Quercus nuttalli: similar to the pin oak; grows in damp sites in Mississippi River basin
oak: a deciduous tree of the genus Quercus; has acorns and lobed leaves

Other hypernyms of Quercus nuttalli include oak tree.

Quercus nuttalli (noun)	oak (noun)
similar to the pin oak; grows in damp sites in Mississippi River basin	a deciduous tree of the genus Quercus; has acorns and lobed leaves
	the hard durable wood of any oak; used especially for furniture and flooring