Natural Notes: A History of some of our most common urban "weeds"
Did you know that Illinois has a state "nickname?" In fact, most state's do, and the nickname for Illinois is the "Prairie State." A prairie is an open grassland without much trees that thrives in semi-arid climates, or in the case of Illinois, in areas frequented by wildfires (figure 1). Wildfires prevent encouragement of woody trees and shrubs to allow sun-loving and deep-rooted prairie grasses and flowers to thrive. Illinois at one point was covered with about 60% tall-grass prairie, but today less than 1% remains. The city of Chicago was once a mixture of wetlands and prairies with small patches of forest. Figure 1: Tallgrass prairie in the northwest suburbs of Chicago. Over time, however, and with European colonization and eventual industrial development, the landscape and the flora and fauna found upon it changed dramatically. Removal of topsoil, chemical pollution, introduction of non-native and invasive plants and other anthropomorphic cha