Tsuga canadensis (eastern hemlock) is a medium, upright, evergreen tree that is found in mountain ranges throughout the eastern United States and Canada. The needles are short, held in pairs, have a shiny dark green color from above, and feature two white (stomata) bands on their undersides. Small rounded cones turn brown in early fall. Tsuga canadensis is ornamentally valuable as a shade tree or as part of a naturalized planting but there are a few things that this species struggles with in the landscape. This plant is intolerant of pollution, salt, heat, and drought. It suffers from a debilitating exotic pest called the woolly adelgid which has decimated wild populations, but can be treated with horticultural oils in cultivated landscapes if the time and capital is available.