Carpinus betulus vs hornbeam

Carpinus betulus and hornbeam both are nouns.

Word	Noun	Adjective	Verb	Adverb
Carpinus betulus	Yes	No	No	No
hornbeam	Yes	No	No	No

As nouns, hornbeam is a hypernym of Carpinus betulus; that is, hornbeam is a word with a broader meaning than Carpinus betulus:

Carpinus betulus: medium-sized Old World tree with smooth grey bark and leaves like beech that turn yellow-orange in autumn
hornbeam: any of several trees or shrubs of the genus Carpinus

Carpinus betulus (noun)	hornbeam (noun)
medium-sized Old World tree with smooth grey bark and leaves like beech that turn yellow-orange in autumn	any of several trees or shrubs of the genus Carpinus