Non-native plants are those that naturally occur on continents other than North America. This section includes both woody stemmed and herbaceous (forbs) plants. Many popular spring bulbs, such as tulips and narcissus, are non-native plants. Sometimes, non-native plants can become a nuisance and can actually damage ecosystems by out competing native plants and, thus, altering the food sources and nesting sites available for native animals. Such ‘problem plants’ are termed invasive exotics. A couple of examples of invasive exotics include bush honeysuckle and garlic mustard. Unfortunately, this list is far from complete.