Pitcher's thistle (Cirsium pitcheri) – This plant is listed as threatened, and is endemic to the Great Lake Region. Pitcher's thistle can be seen growing on most sandy beaches around Beaver Island. An easy way to distinguish Pitcher's thistle from other thistles is the plant's silvery-white color, which helps it tolerate the heat and sun of the beach. Hairs cover the plant to help retain water and to reflect the sun's harmful rays. An interesting fact about Pitcher's thistle is that it is monocarpic, meaning it grows and matures for several years, produces seeds once in its lifetime, and then dies. Flowers are light purple or pink and bloom June through September. wormwood, another dune plant commonly found on Beaver Island, is often mistaken for Pitcher's thistle when not in bloom; however, it has more finely divided leaves.