castor bean plant vs castor bean

castor bean plant and castor bean both are nouns.

Word	Noun	Adjective	Verb	Adverb
castor bean plant	Yes	No	No	No
castor bean	Yes	No	No	No

castor bean plant (noun)	castor bean (noun)
large shrub of tropical Africa and Asia having large palmate leaves and spiny capsules containing seeds that are the source of castor oil and ricin; widely naturalized throughout the tropics	the toxic seed of the castor-oil plant; source of castor oil