beach plum bush vs beach plum

beach plum bush and beach plum both are nouns.

Word	Noun	Adjective	Verb	Adverb
beach plum bush	Yes	No	No	No
beach plum	Yes	No	No	No

As nouns, beach plum bush and beach plum are synonyms defined as:

beach plum bush and beach plum: seacoast shrub of northeastern North America having showy white blossoms and edible purple fruit

Other synonyms of beach plum bush include Prunus maritima.

beach plum bush (noun)	beach plum (noun)
seacoast shrub of northeastern North America having showy white blossoms and edible purple fruit	small dark purple fruit used especially in jams and pies
	seacoast shrub of northeastern North America having showy white blossoms and edible purple fruit