Giant hogweed

The giant hogweed is a massive herbaceous plant. Known for its size, the plant can grow from 10 to 15 feet tall. It has hollow stems which are 2-4 inches in diameter. The stalks and stems produce stiff bristle-like hairs, the stems also have spots. These spots are dark reddish-purple and raised. Hogweed plants have compound, lobed leaves which can group up to 5 feet in width. These dark green leaves are ternate or ternate-pinnate and coarsely toothed. At the base of the leaf stalk there are white coarse hairs. An individual cluster can grow to 2.5 feet in diameter. The plant also produces a toxic sap which is harmful to humans.

Ecology
Giant Hogweed is native to the Caucasus Mountains and southwest Asia. It was introduced in 1917 to the U.S., Europe, Canada, and the U.K. for ornamental purposes. In the U.S. it was brought to Washington, Oregon, Illinois, New York, Pennsylvania, Vermont, Massachusetts, and Connecticut. Giant hogweed prefers moist, rich soil and semi-shade but thrives in full sun as well. It can survive with flooding. Capable of rapid colonization this plant typically found growing in backyards, ravines, streams, woods or forests, roadsides, vacant lots, and rivers. It is a highly competitive invasive species that crowds out native plant and can co-exist with other aggressive invasive species by forming dense canopies. Hogweed is also known to increase soil erosion.

Other
Giant Hogweed is most commonly known for its massive size but also its toxic sap. It's sap is clear and watery and contains toxins which can cause photodermatitis. If the sap comes into contact with skin and is then exposed to sunlight and moisture, skin irritaion , painful burns, blisters, purple or blackened scars , or permanent scarring can occur. And in some cases can even result in blindness. Contact with the sap can occur when one brushes against the bristles on the stem or breaks the stems or leaves.