lemon-scented gum vs eucalypt

lemon-scented gum and eucalypt both are nouns.

Word	Noun	Adjective	Verb	Adverb
lemon-scented gum	Yes	No	No	No
eucalypt	Yes	No	No	No

As nouns, eucalypt is a hypernym of lemon-scented gum; that is, eucalypt is a word with a broader meaning than lemon-scented gum:

lemon-scented gum: similar to but smaller than the spotted gum and having lemon-scented leaves
eucalypt: a tree of the genus Eucalyptus

Other hypernyms of lemon-scented gum include eucalyptus, eucalyptus tree.

lemon-scented gum (noun)	eucalypt (noun)
similar to but smaller than the spotted gum and having lemon-scented leaves	a tree of the genus Eucalyptus