Illustration of spirals found on a sunflower. The number of clockwise and counterclockwise spirals, or florets, on a sunflower are consecutive Fibonacci numbers. Fibonacci numbers are defined as a sequence of integers in which each subsequent number is the sum of the two previous numbers in the sequence. For example: 0,1,1,2,3,5,8,13,21,34,55,89,144, etc. This sequence of number is found in many biological settings.