Name of the Frame surrounding PartyFrames

[Tullamore]

I want to hide the full group window. But, for the love of god, wasn't able to find the name of the frame that is responsible for displaying the background:


PartyFrame1:Hide();
PartyFrame2:Hide();
PartyFrame3:Hide();
PartyFrame4:Hide();

Will hide the healthbar, portrait, etc for each party member. The greyish background with the rounded edges is still visible however.
Anybody happen to know if that is an actual frame, and if so, what is its name. Or is the background added at runtime in code, and if so, how can I hide it?

[Wobin]

I'm only looking at the xml files, but try PartyMemberBackground

[Zheele]

Or you can just disable the "Party Frame Background" in the interface options.