A mathematical series that is obtained by adding the two previous elements of the series, as in 1, 2, 3, 5, 8, 13, 21, etc. The interlocking spirals found in many plant structures, such as the fruit arrangement in a sunflower head, or the sections on a pineapple, are described by this series. The series was discovered by the Italian mathematician Leonardo Fibonacci (c. 1180–c. 1250), who was also influential in introducing Indo–Arabic numerals to Europe. Fibonacci lived in Pisa.
Subjects: Plant Sciences and Forestry.