RE: in many flowers the number of petals is a fibonacci number (or is such a number repeated twice, in two sets):
3 petals: lily, iris
Iris, lily(s) and tulips all have 3 petals/
half the "flower" is a modified, colored sepel A slightly different structure. -- sepal are most familier in roses (which have 5, the green covers to the rose bud)
some plants have modified sepals.. so, three of the lilies "petals' are really "covers' to the three petals of the flower.
same in tulips, and iris's, and lots of other flowers.
flowers generally have 1 to 1 ratio of sepals to petals.. but in modified forms, the ratio is lost. so old, simple roses (a tudor rose, say) has five petals but many modern roses have any number of petals, following a fibonacci series number. there are also "double forms of lilies", with 6 or 9 petals (total appearence, 9 or 12) but the number of sepals remains the same.
