soapberry tree vs soapberry

soapberry tree and soapberry both are nouns.

Word	Noun	Adjective	Verb	Adverb
soapberry tree	Yes	No	No	No
soapberry	Yes	No	No	No

As nouns, soapberry tree and soapberry are synonyms defined as:

soapberry tree and soapberry: a tree of the genus Sapindus whose fruit is rich in saponin

soapberry tree (noun)	soapberry (noun)
a tree of the genus Sapindus whose fruit is rich in saponin	a tree of the genus Sapindus whose fruit is rich in saponin