Definition of helianthus
1 capitalized : a genus of tall erect or sometimes much-branched American annual or perennial herbs (family Compositae) comprising the sunflowers and having flower heads with purple or yellow disk flowers and showy yellow sterile rays — see jerusalem artichoke
2 plural -es : any plant of the genus Helianthus
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Origin and Etymology of helianthus
New Latin, from 1heli- + -anthus
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