This New England Wild Flower Society on line class will cover the criteria botanists use to determine whether plants are native to a region or introduced. Research botanist Arthur Haines will explain the shortcomings of each criterion to help explain the need for using suites of criteria. Given that the flora has always been changing (and likely always will), static benchmarks are problematic. The class will also include a brief discussion of global biodiversity and the problem of human-centric viewpoints. $10 for NEWFS members, $13 for nonmembers. Class takes place Wednesday, February 21 at 1 pm. Sign up at http://www.newenglandwild.org/learn/our-programs/live-webinar-our-dynamic-flora