marmalade plum vs marmalade tree

marmalade plum and marmalade tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
marmalade plum	Yes	No	No	No
marmalade tree	Yes	No	No	No

marmalade plum (noun)	marmalade tree (noun)
brown oval fruit flesh makes excellent sherbet	tropical American tree having wood like mahogany and sweet edible egg-shaped fruit; in some classifications placed in the genus Calocarpum