Sunflower patterns are obtained using a Fermat spiral with a golden angle spacing

fermat-spirale.py

import numpy as np
from matplotlib import pyplot as plt
%matplotlib inline

n = range(1, 100)
phi = (3 - np.sqrt(5)) * np.pi

for a in [0.98, 0.985, 0.99, 0.995, 1, 1.005, 1.01, 1.015, 1.02]:
    fig = plt.figure()
    r = np.sqrt(n)
    theta = a * phi * n
    ax = fig.add_subplot(1, 1, 1, projection='polar')
    c = ax.scatter(theta, r, alpha=0.75)