Lactuca sativa capitata vs iceberg

Lactuca sativa capitata and iceberg both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lactuca sativa capitata	Yes	No	No	No
iceberg	Yes	No	No	No

Lactuca sativa capitata (noun)	iceberg (noun)
distinguished by leaves arranged in a dense rosette that develop into a compact ball	lettuce with crisp tightly packed light-green leaves in a firm head
	a large mass of ice floating at sea; usually broken off of a polar glacier