Peterson Stem

[Flatfish]

Hello
On the stem of this Peterson below, what is the sort of flared part. I am talking about the piece of black stem pretty much in the middle of the photo.
Is it just decorative?

 

[Streeper541]

That is referred to as a "shoulder" and is decorative.

 

[Chasing Embers]

Also called an expansion ring. Often used on freehand and fancy stems.

 

[bullet08]

That's for ladies' pleasure, along with P-lip.

 

[ThermionicScott]

I always assumed it was for getting a good grip on the stem when pulling it out of an army mount. That's what I use it for, anyway.

 

[warren]

It's both practical, stem pulling, and eye pleasing for me. Well, if not overdone.

 

[Flatfish]

Saw a rusticated straight Peterson shape 31 (I think) in the window of a shop last Saturday. It had a shoulder and I was just curious what it was.
It remains in the shop window in case anyone was wondering, but it looked quite nice.