In just a few hours on Sunday, June 11 from 9 – 1, Kyle Port, Manager of Plant Records at the Arnold Arboretum of Harvard University, will teach you to identify 90 percent of the trees growing in Boston, both native and nonnative. Beginning in the classroom in the Hunnewell Building, you will briefly review the characteristics of the 25 most common trees and learn the botanical terminology necessary to describe them. You will then walk the grounds of the Arboretum to look at mature specimens of these trees.Bring a notebook or clipboard for this information-rich program. Fee $45 member, $60 nonmember. Register at www.my.arboretum.harvard.edu.