pigeon-pea plant vs pigeon pea

pigeon-pea plant and pigeon pea both are nouns.

Word	Noun	Adjective	Verb	Adverb
pigeon-pea plant	Yes	No	No	No
pigeon pea	Yes	No	No	No

As nouns, pigeon-pea plant and pigeon pea are synonyms defined as:

pigeon-pea plant and pigeon pea: tropical woody herb with showy yellow flowers and flat pods; much cultivated in the tropics

Other synonyms of pigeon-pea plant include cajan pea, Cajanus cajan, catjang pea, dahl, dhal, red gram.

pigeon-pea plant (noun)	pigeon pea (noun)
tropical woody herb with showy yellow flowers and flat pods; much cultivated in the tropics	small highly nutritious seed of the tropical pigeon-pea plant
	tropical woody herb with showy yellow flowers and flat pods; much cultivated in the tropics