import numpy as np
import matplotlib.pyplot as plt

x,y = np.linspace(-3,3,100),np.linspace(-3,3,100)
X,Y = np.meshgrid(x,y)
U = -1 - X**2 + Y
V = 1 + X - Y**2
speed = np.sqrt(U*U + V*V)

start = [[0,0], [1,2]]

fig0, ax0 = plt.subplots()

strm = ax0.streamplot(x,y, U, V, color=(.75,.90,.93))

# note: moving away from the edge is a workaround
#bump = 50*np.finfo(float).eps
bump = 0
rightside_points = [[i,3-bump] for i in np.linspace(-3,3,5)]
bottomside_points = [[3-bump,i] for i in np.linspace(-3,3,5)]

rightside_mat = np.vstack(rightside_points)
bottomside_mat = np.vstack(bottomside_points)

# start points on right side do not work
ax0.streamplot(x,y, U, V, start_points=rightside_points, color="crimson", linewidth=2)
ax0.plot(rightside_mat[:,0], rightside_mat[:,1], "gx", markersize=12, label="upper")

# start points on bottom side do not work
ax0.streamplot(x,y, U, V, start_points=bottomside_points, color="crimson", linewidth=2)
ax0.plot(bottomside_mat[:,0], bottomside_mat[:,1], "mx", markersize=12, label="right")

plt.legend()
plt.show()