Parametric Parabolic Mushroom

A mushroom made of a rotated parabola and a cylindric stem.
The parabola is actually a projection of a cone cut at a certain angle.
There are two samples of such mushrooms:

1. Parametric_Parabolic_Mushroom_1 is being generated using these parameters:
Ht=400; //Total height
R=120; //Radius of mushroom
Hs=200; //Height of stem
Rs=30; //Stem radius
s=100; //Smoothness

2. Parametric_Parabolic_Mushroom_2 is being generated using these parameters:
Ht=500; //Total height
R=300; //Ra