A bin of Urtica Diocia, or stinging nettle that was established in 2010, and returned to take over three bins in 2011. The self defense systems of this native flowering perennial are tiny, hollow stinging hairs called Tricomes. The Tricomes, found in the leaves of the plant, act like tiny hypodermic needles, and shoot Histimines and other irritating chemicals into skin that comes in contact with the plant. This plant has an extensive medicinal and culinary history in North America, is 10% protein, and, like other wild edibles introduced to the Parts and Labour roof, it manages to thrive despite the harsh temperature fluctuations up top. It also sneak attacks the chefs fingers.
Here's a site with a great deal of nettle lore, including the benefits of being flogged with the plant?