How to make a three-sepals standard origami calyx

(page 7)

11th picture of Three-sepals standard origami calyx

Unfold three previous valley-folds.

Prepare to apply a so-called "petal-fold"

This is the crease pattern (CP) for petal-fold.

12th picture of Three-sepals standard origami calyx

Lift the bottom corner upwards.

Where Roses would not dare to go,
What Heart would risk the way --
And so I send my Crimson Scouts
To sound the Enemy --