Pitcher plants are fascinating! I'm familiar with only one spot in Oregon where they grow, although I know there are other spots. I sketched these at the Darlingtonia Botanical Wayside just north of Florence, Oregon.
Growing pitcher plants takes just the right conditions -- a cool seep in poor soils and relatively shady. The plants are surprisingly large. Those bulbous heads are as big as medium sized oranges.
Pitcher plants attract insects. Once inside the small opening they slip down the hollow stem and are dissolved in a chemical brew. Nutrients from the insects are important for healthy pitcher plants.