Giant sunflower and Helianthus

Giant sunflower noun - Very tall American perennial of central and the eastern United States to Canada having edible tuberous roots.

Helianthus and giant sunflower are semantically related. In some cases you can use "Helianthus" instead a noun phrase "Giant sunflower".

Helianthus noun - Any plant of the genus Helianthus having large flower heads with dark disk florets and showy yellow rays.

Giant sunflower and helianthus are semantically related. Sometimes you can replace phrase "Giant sunflower" with "Helianthus", this terms are similar.