Flower thing #2

Another OpenSCAD distraction. This time I wanted to show my daughters the interesting aspects of Fibonacci numbers & came across this video on YouTube:
https://www.youtube.com/watch?v=FOuHWXN8g2s (Thanks Eric Buijs!)
I have shamelessly appropriated his code for placement of petals/leaves around a sphere. The code for drawing a rod between two points is from here:
http://forum.openscad.org/Rods-between-3D-points-td13104.html (David Eccles).
The only part I can claim as my own is the petal/leave drawing module. This is an intersection between a linear_extrude (creates the lateral shape) and a rotate_extrude of 2d formulas. This unfortunately makes the render very computationally expensive & it takes a long time to render for nr leaves > 100 &/or high values of $fn.