Trees are the great form of nature and this the shape made many inspiration for numerous artists of mathematical art. I've posted several collections of fractal trees and pythagoras trees. And we've also met with combination of tree-like shape with spiral. Spirals are one of basic mathematical shapes and they are harmoniously match to branchy tree figure. Also spiral is the shape that very close to fractals.
Below, you can see several spiral shapes, which look very interesting for me. They are not true fractals, but they make sence of great curly figures. Click on images to see them in better quality.
Black spiral tree
© Willy Deganello
Logo of the site The Spiral Tree
Curly cone tree from article of Cameron Browne about spiral space filling
Spiral dotted tree
A fractal-like spiral tree. Smaller branches repeat their parent branch.
Images were found at