Author(s): P. C. BHOWMIK AND 1R. S. CHANDRAN

Abstract: Introduced from Europe for its unique appearance, Heracleum mantegazzianum Sommier & Levier (giant hogweed) is becoming increasingly prevalent across North America especially in the Northwestern and Northeastern States of the United States and Canada. Currently it is found along riverbanks, roadsides, waste places, and abundant lands. It is a member of the carrot family, Umbelliferae (Apiaceae). It is a biennial or a monocarpic short-lived perennial. It generally flowers in its third year of growth. It resembles different plant species during different stages of its life cycle and is often mistakenly planted as an ornamental due to the attractive flower heads it produces. Heracleum mantegazzianum is closely related to Heracleum lanatum Michx. (cow parsnip). It poses a threat to natural ecosystems and is also a weed in agricultural and urban areas. This species represents an increasing public health hazard. The plant exudes a clear watery sap which contains furanocoumarins. Contact with H. mantegazzianum can cause photophotodermatitis, a serious skin inflammation caused by UV photo-activation, resulting in severe burns to the affected areas and severe blistering. Control measures must be taken in order to prevent its further infestations. The perennial nature of H. mantegazzianum and toxicity of the plant sap limits mechanical control options. Chemical control options include postemergence application of growth regulator herbicides, glyphosate or trichlopyr, although limited information on its control is available. Ability to identify this weed and understand its biology will aid successful management efforts. Public education to dissuade gardeners from planting this attractive but noxious plant in their gardens is also necessary. This species should be watched carefully for its future infestation and subsequent spread as an invasive weed in agricultural and urban areas.

Download Full Article: Click Here