The problem with Harvard University’s collection of glass flowers, explains professor of botany Donald H. Pfister, is that they’re too realistic. “When they’re photographed, they just look like plants,” he says, ruefully. “So how do you make a photo book that lets people know that these are actually glass models?” Even the first director of Harvard’s Botanical Museum, George Lincoln Goodale, was initially fooled by the models. During an 1886 trip to Germany to visit the home of glassmakers Leopold and Rudolf Blaschka, he saw what he assumed to be a vase of blooming, freshly-cut orchids. In truth, each...