The blue-helmeted grape hyacinths stand at attention as Paul Meyer rides by in the arboretum’s golf cart, his pollen-hued tie flapping behind him in the breeze. It is one of those rare spring days in Philadelphia—a mild respite between a winter that overstayed its welcome and the muggy summer ahead. As we putter along the grounds, the saucer magnolias drop pastel confetti. A mother photographs her son by the weeping Higan cherry. Even the lesser celandines, wildflowers that, in Meyer’s words, are “taking over the world,” are putting on a golden show. But we are not here just to gape at the blossoms.

Meyer pulls up to a paperbark maple, and we get out to take a closer look at the tree, known for its coppery, peeling layers. “It lacks vigor,” he says. “See how short the growth increments are? I believe we’re seeing evidence here of inbreeding depression.” This planting preceded Penn’s ownership of the arboretum and shows the importance of intra-species diversity. Until recently, all the paperbark maples in this country were descended from a few collected by the famous British plant explorer E.H. Wilson; the arboretum collected more on a trip to China in 1994, broadening the genetic stock.

Top, left : Japanese camellia from South Korea; top right: Royal azalea from Korea; above left: Popular magnolia hybrids of Asian species; above right: Heritage river birch, native to U.S.

Plant hunting in previous centuries focused on the discovery and collection of plants unknown to Western science. Soybeans, for example, were virtually unknown in the United States until Frank Meyer introduced them from China while working for the U.S. Department of Agriculture. Though today’s plant explorers may occasionally find a species new to Western cultivation, they focus on recollecting new genetic forms of known plants. “Much of what we grow in this country comes from very limited genetic source material. By recollecting, we’re broadening that material,” Paul Meyer says. Variety within and across species can yield multiple benefits, from an increased ability to tolerate extreme temperatures to a stronger resistance to disease and insects.

“There is safety in diversity; there are dangers in monoculture,” Meyer says, giving the example of Dutch elm disease, which all but wiped out what had been the most popular street tree in America. “The more we tend to plant the same old things over and over again, the more fragile our urban forests become. You could make the same argument for a suburban planting or an agricultural planting.”

There’s no danger of monoculture at the arboretum. Most of its plants come from China, the United States, Korea, Japan, and Armenia, but there are also specimens from Bhutan, Iran, Mexico, Finland, Morocco, and Afghanistan, among other places.

Before Penn took them over in 1933, the grounds belonged to the estate of John and Lydia Morris. Unmarried siblings whose father had owned what was later named the Port Richmond Iron Works, the Morrises were true Victorian collectors. They collected Chinese pottery, Roman glass, Mediterranean coins, garden styles, and many plants. “They were really interested in the world around them,” says Meyer, “and one way they expressed this interest was through these collections.” (They also had the vision that their plant collections would be used as an educational tool for others one day.)

According to Robert Gutowski, the arboretum’s director of public programs, the Morrises acquired some plants on their own travels to Europe and Asia, including cherries John Morris gathered himself in the mountains of Japan. They also bought and sent home ferns from India, bonsais from Japan, and Michaelmas daisies from England. “Matters of homeland security didn’t apply in those days,” Gutowski notes.

The siblings were not exactly rough-and-tumble adventurers—Lydia traveled with her tea set, and they stayed with rajas and other royalty when possible. But “relative to their life here in the United States, they were roughing it,” given the state of travel lodgings at the time, Gutowski says. They also exchanged specimens with Harvard’s Arnold Arboretum and Wilson (who later joined that institution from England’s Veitch Nursery), among others.

Penn’s botany department ran the Morris Arboretum from 1933 until 1975, at which point it became a multidisciplinary research center of the University. After decades of almost no plant exploration, the arboretum sent Paul Meyer (then curator) to Korea in 1979. Since then, the arboretum staff has taken more than a dozen collecting trips—all in collaboration with other institutions. In 2002, for example, Meyer traveled to Armenia with USDA scientists helping that country develop agricultural products for the world market while collecting varieties of pear and other plants. A number of expeditions have been arranged through the North American-China Plant Exploration Consortium, which includes the Morris Arboretum as well as several botanical institutions in the United States and China.

 

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2004 The Pennsylvania Gazette
Last modified 07/01/04

FEATURE:
The Global Garden
By Susan Frith
Photography by Candace diCarlo

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