Zinnias are annuals, shrubs, and sub-shrubs native primarily to North America, with a few species in South America.^[6]: 338 Most species have upright stems but some have a lax habit with spreading stems that mound over the surface of the ground. They typically range in height from 10 to 100 cm tall (4" to 40").^[5] The leaves are opposite and usually stalkless (sessile), with a shape ranging from linear to ovate, and a color ranging from pale to medium green. Zinnia's composite flowers consist of ray florets that surround disk florets, which may be a different color than the ray florets and mature from the periphery inward.^[7] The flowers have a range of appearances, from a single row of petals to a dome shape. Zinnias may be white, chartreuse, yellow, orange, red, purple, or lilac.^[5]