The graph shows a walk along a rose in steps of degrees (including rotations) with either or petals, according to whether is odd or even. Varying scales the degrees.
For more information see:
S. Wagon, Mathematica in Action, New York: W. H. Freeman, 1991.
P. M. Maurer, "A Rose Is a Rose...," The American Mathematical Monthly, 94(7), 1987 pp. 631–645.