Heracleum Mantegazzianum (IMAGE) Helmholtz Association Caption The Giant Hogweed (Heracleum mantegazzianum) are up to four meters high. It can cause third-degree burns because of the extremely aggressive sap inside the plant. Credit Photo: Petr Pysek/Institute of Botany, Academy of Sciences of the Czech Republic Usage Restrictions None License Licensed content 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.