Modified Pitchfork bifurcation diagram of

$$\dot x = r x + x^3 - x^5$$

F1[r_] := Sqrt[1 - Sqrt[1 + 4 r]];
F2[r_] := Sqrt[1  Sqrt[1 + 4 r]];
Plot[{F1[r], -F1[r], F2[r], -F2[r], 0}, {r, -1, 2}]