Leonardo Pisano Fibonacci 1170 – 1250
1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 etcThis sequence is known as the Fibonacci series, and is well known in mathematics.
Each number is the sum of the previous two. The ratio of successive pairs tends to the so-called golden section. Plants do not know about this – they just grow in the most efficient ways.
Many plants show the Fibonacci numbers in the arrangement of the leaves around the stem.
Some pine cones and fir cones also show the numbers, as do daisies and sunflowers.
Why do these arrangements occur in nature? In the case of leaf arrangement, or phyllotaxis, some of the cases may be related to maximizing the space for each leaf, or the average amount of light falling on each one.
Even a tiny advantage would come to dominate, over many generations. In the case of close-packed leaves in cabbages and succulents the correct arrangement may be crucial for availability of space.
An example of Fibonacci on a Monkey Puzzle Tree where every part of the branch captures the maximum amount of daylight.
Please see other plants on my interactive plant finder, identification and pruning guide website www.rightplants4me.co.uk
Photography Neil Bromhall. Complete Garden plant advice CD-ROM