gum tree vs tupelo

gum tree and tupelo both are nouns.

Word	Noun	Adjective	Verb	Adverb
gum tree	Yes	No	No	No
tupelo	Yes	No	No	No

As nouns, tupelo is a hyponym of gum tree; that is, tupelo is a word with a more specific, narrower meaning than gum tree:

gum tree: any of various trees of the genera Eucalyptus or Liquidambar or Nyssa that are sources of gum
tupelo: any of several gum trees of swampy areas of North America

Other hyponyms of gum tree include liquidambar, eucalypt, eucalyptus, eucalyptus tree, tupelo tree.

gum tree (noun)	tupelo (noun)
any of various trees of the genera Eucalyptus or Liquidambar or Nyssa that are sources of gum	any of several gum trees of swampy areas of North America
	pale soft wood of a tupelo tree especially the water gum