helianthus(n = noun.plant) sunflower - any plant of the genus Helianthus having large flower heads with dark disk florets and showy yellow rays;
is a kind of flower
is a member of genus helianthus
has particulars: helianthus angustifolius, swamp sunflower, common sunflower, helianthus annuus, mirasol, giant sunflower, helianthus giganteus, indian potato, tall sunflower, helianthus laetiflorus, showy sunflower, helianthus maximilianii, maximilian's sunflower, helianthus petiolaris, prairie sunflower, girasol, helianthus tuberosus, jerusalem artichoke, jerusalem artichoke sunflower

   any plant of the genus Helianthus having large flower heads with dark disk florets and showy yellow rays. [WordNet 1.5]

helianthus, n. any plant of the genus Helianthus, including the sunflower and Jerusalem artichoke.

Etymology:
mod.L f. Gk helios sun + anthos flower

genus helianthus, helianthus angustifolius, helianthus annuus, helianthus giganteus, helianthus laetiflorus, helianthus maximilianii, helianthus petiolaris, helianthus tuberosus