Jul 4, 2012

Giant Hogweed - up the River but not (yet) down the Bay coast yet

Giant Hogweed - up to 14 feet tall

This aggressive invasive plant superficially resembles Queen Anne's Lace, but looms up to 14 feet tall. (Queen Anne's Lace maxes out at 3 feet tall.)The howeed stems are up to  2 & 1/2 inch thick stems, supporting leaves up to 5 feet wide. The annual weed has multiple flower heads per plant. (QA's Lace has just one flower per plant). 

Giant Hogweed sap  is highly toxic.  According to the video in the BDN article and other sources, if the bamboo-like stems are broken open,  skin contact with the sap causes skin irritation, lasting hypersensitivity to sunlight  (see blistered arm)   Even "brushing up against and breaking open the robust hairs on the plant's leaves" can trigger the irritation, according to a Maine Cooperative Extension report. Blindness has occurred as a result of the sap touching eyeballs.

Queen Anne's Lace - up to 3 feet tall

Each Giant Hogweed plant produces 100s of floatable seeds. It has a capacity to colonize Knox,Waldo  and Hancock counties if the seeds come down the river and survive in brackish water long enough to reach shore.

If you live along Penobscot Bay or elsewhere in Maine and identify this pernicious invader, please report the sighting to State Horticulturist Ann Gibbs at the Maine Department of Agriculture at 207-287-3891  or email ann.gibbs AT maine.gov  They will help organize renoval
Because of the dangerousness of the sap, before taking on Giant Hogweed,  please review Maine Department of  Agriculture's  "Homeowners' Guide to Managing Giant Hogweed" (2 page pdf) 

Giant Hogweed was introduced into the United States  from the Near East in the early 1900s as an arboretum curiosity.

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