What Is Arugula?

I found this Newsweek story quite funny:

Aug. 20-27, 2007 issue - On a sunlit Friday afternoon in July, Barack Obama stopped by Beverly Van Fossen's farm in Adel, Iowa, to speak about "rural issues." It was standard Hawkeye State stumping—until the senator took a stab at sympathizing with farmers whose crop prices have stagnated. "Anybody gone into Whole Foods lately and see what they charge for arugula?" he asked. Unfortunately, Adel isn't exactly arugula country. "Someone near me whispered, 'What's arugula?' " says Van Fossen, 74. " 'You can't find that in Iowa'." Same goes for Whole Foods. The closest locations, reported The New York Times that evening, are in Omaha, Neb.; Kansas City, Kans., and Minneapolis. Whoops.