Definitely something to file away in the dusty attic of your brain. Hogweed that can blind humans found in Calhoun County, MI Health officials in Calhoun County are advising caution after the dangerous giant hogweed plant was spotted in the county. The Calhoun County Public Health Department said Monday that the plant was found in Pennfield Township nearly Battle Creek, and was removed from the site. The Battle Creek Enquirer reports the sap on the plant's leaves, roots, flower heads, seeds and stem hairs can cause permanent blindness if it gets in the eyes. The sap can also cause blistering and scarring if it gets on bare skin. Health officials say to wash skin if it comes in contact with the plant and immediately flush eyes with water, and promptly seek medical attention. The plant can grow to 18 feet tall, has a green stem with bristles and dark red or purple spots, and has a white flower.