The seed pod below should look a bit familiar, if you read my previous post about Asclepias syriacus.
These pods are from another milkweed, Asclepias phsyocarpa, more commonly referred to as balloonplant or swan plant. These photos were taken the Sunday before Thanksgiving and, as you can see, the plant was still blooming, despite below-freezing temps.
I can't dig up any information as to why the plant is called swan plant, but Asclepias is derivative of the Greek god of healing, Asklepios. Phusa or physa is Greek for bladder, which refers to the shape of the seed pod, while karpos is Greek for fruit.