Sunflower is not a single flower. Explain.

(N/A) $ \Rightarrow $ Sunflower is not a single flower but a type of inflorescence known as a capitulum (or head), in which the receptacle is flattened.
It consists of many small, sessile flowers called florets.
The youngest florets are in the centre, and the oldest are located towards the periphery (centripetal arrangement).
The entire group of florets is surrounded by a whorl of bracts called an involucre.
Two types of florets are seen in a sunflower:
$(i)$ Ray florets: These are arranged on the periphery of the receptacle. They possess large, yellow, strap-like petals. These florets are typically female (pistillate), sessile, and zygomorphic.
$(ii)$ Disc florets: These are located in the centre of the receptacle. They are bisexual and actinomorphic.