It's a Nepenthes, one of the pitcher plants. Water and digestive juices fill the buckets and digest insects that fall into them. Nepenthes are tropical and like high humidity and warmth; I don't think they're especially easy to keep happy in the house. WW Here is a link that might be useful: Nepenthes

Mary Ellen, i think you are talking about a Mandevillia. No idea how to grow it in Chicago and the notes in the link might not be appropriate for your climate. "winter" here and my plant has stopped flowering and is waiting for spring, but note that winter here is not all that cold. Here is a link that might be useful: Mandevillia notes

Thanks for the info. I have looked up this ragweed and I am sure you are correct. We are cutting it down right away before it has a chance to bloom and send its pollen everywhere.

Finally tracked this down: a Pedilanthus, probably P. palmeri. See link below. It was obvious it was something in the Euphorbiaceae, with a stalked, 3-celled ovary like that, and the bracts and inflorescence structure suggested Euphorbia and its close allies (subfam. Euphorbioideae tribe Euphorbieae). Here is a link that might be useful: Pedilanthus