Any of about 22 species of herbaceous plants and shrubs that make up the genus Zinnia (composite family), native mainly to North America. Where native, they are perennial; elsewhere they are annual. Zinnias have stiff, hairy stems and oval or lance-shaped leaves arranged opposite each other and often clasping the stem. The numerous garden varieties grown for their showy, solitary flowers come from the species Z. elegans. Garden zinnias range from dwarf compact plants (less than 1 ft, or 30 cm, tall), with flowers 1 in. (2.5 cm) in diameter, to giant forms (up to 3 ft, or 1 m, tall), with flowers up to 6 in. (15 cm) across