What are the petal-like ray flowers on a daisy or sunflower head?

The petal-like structures found on the outer edge of a daisy or sunflower head are not individual petals, but are actually separate, individual flowers known as ray flowers.21

In the Asteraceae family, what appears to be a single flower is actually a compact inflorescence (a head) composed of many small flowers called florets. In a radiate head, these ray flowers are arranged in one or more marginal rows surrounding the central disk flowers. Each ray flower possesses a modified, flat, and elongated corolla that extends outward, creating the appearance of a petal. Unlike the central disk flowers, which are typically tubular, these ray flowers are often pistillate (female) or neutral, serving primarily to attract pollinators to the composite head.231