Quercus ellipsoidalis vs oak

Quercus ellipsoidalis and oak both are nouns.

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

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

Quercus ellipsoidalis: small to medium deciduous oak of east central North America; leaves have sharply pointed lobes
oak: a deciduous tree of the genus Quercus; has acorns and lobed leaves

Other hypernyms of Quercus ellipsoidalis include oak tree.

Quercus ellipsoidalis (noun)	oak (noun)
small to medium deciduous oak of east central North America; leaves have sharply pointed lobes	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