The folk name for Loosestrife is "Lambskill",as it is believed it will kill young sheep.I do not know if this is true, but I do know it grows in abundance on the Shawsheen , and it has choked out the native plants. It is present because it was in the wool imported from the U.K.and woven in the mills along the river at the turn of the century.When the wool was washed, the seed was deposited in the river.Each mature plant is capable of producing tens of thousands of seeds, making it's spread all but impossible to stop.Lately, efforts to control it include an imported beetle which dines exclusively on the plant.This method should be considered for this river.