What is often called a sunflower flower is an inflorescence.

An excerpt from the article 15 facts about sunflower

It is composed of many small, single, five-petal flowers. Sunflower flowers create a very interesting, mathematical pattern. Each flower is located at 137.5 degrees in relation to the next one, i.e. the golden angle. The flowers thus form a system of connecting spirals, where the number of left and right spirals are successive numbers in the Fibonacci sequence.