- Any of various plants of the genus <em>Zinnia</em> of the composite family, native to tropical America and widely cultivated for their showy, colorful flower heads.
- A genus of composite plants, of the tribe <em>Helianthoideæ</em>, type of the subtribe <em>Zinnieæ.</em>
- [<em>lowercase</em>] A plant of this genus.
- Any plant of the composite genus Zinnia, Mexican herbs with opposite leaves and large gay-colored blossoms. <spn>Zinnia elegans</spn> is the commonest species in cultivation.
- Any of several brightly coloured <xref>flowering plants</xref>, of the genus <xref>Zinnia</xref>, native to <xref>tropical</xref> <xref>America</xref>; <xref>old maid</xref>
- any of various plants of the genus Zinnia cultivated for their variously and brightly colored flower heads