This paper examines why many flowers are five-petaled through the use of a five-petaled model that draws insights from the location of cell clusters at a shoot apex, rather than by way of the Fibonacci sequence or the golden ratio as in the past. The conclusion drawn is that flowers are most likely to be five-petaled, followed by six-petaled; four petals are unstable and almost no flower can be seven-petaled.
flower - cell - petal - leaf - pentagon - Fullerene