Pitchers thistle (IMAGE) University of Southern Denmark Caption Pitcher´s Thistle (Cirsium pitcheri), native to North America, is well-studied. Credit R. Routledge Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.