Maybe we can just stop here since the making of calyx is completed.

 

However, I think a calyx without a stem doesn't make sense. So I will just step out of origami folding-session to explain how to attach a wire-stem to a calyx and to a rose.

 

You need four items:

 

(1) green floral wire-stem: either 16 or 18 gauge would be fine but I prefer 16 gauge since it doesn't bend easily,

(2) 1/2" wide green floral tape,

(3) pliers,

(4) glue.

 

First, bend the wire with pliers.