This is a pitcher plant, called that because it is shaped like a pitcher. An insect is attracted by a rather rank smell and lands on the lip, and slides down a very slick inner surface where enzymes at the bottom “Stomach!” digest it. This provides the plant with needed nitrogen and phosphorus. Sarracenia have been used for medicinal purposes (but don’t try this at home!) To read an article I wrote about carnivorous plants, go to The Breeze, Magazine of the Low Country, South Carolina (February 2020).
Cronesinger.com 