sweet corn vs sweet corn plant

sweet corn and sweet corn plant both are nouns.

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

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

sweet 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 sweet corn include green corn, sugar corn, Zea mays rugosa, Zea saccharata.

sweet 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