green corn vs sweet corn plant

green corn and sweet corn plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
green corn	Yes	No	No	No
sweet corn plant	Yes	No	No	No

As nouns, green corn and sweet corn plant are synonyms defined as:

green corn and sweet corn plant: a corn plant developed in order to have young ears that are sweet and suitable for eating

Other synonyms of green corn include sugar corn, sweet corn, Zea mays rugosa, Zea saccharata.

green corn (noun)	sweet corn plant (noun)
corn that can be eaten as a vegetable while still young and soft	a corn plant developed in order to have young ears that are sweet and suitable for eating
a corn plant developed in order to have young ears that are sweet and suitable for eating