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United States Department of Agriculture

Agricultural Research Service

Congress to Plant National Arboretum's New American Elm That Staves off Dutch Elm Disease / June 6, 1996June 6, 1996 / News from the USDA Agricultural Research Service

ARS scientist  Alden Townsend with Valley Forge elm tree tolerant of Dutch elm disease

Congress to Plant National Arboretum's New American Elm That Staves off Dutch Elm Disease

By Hank Becker
June 6, 1996

WASHINGTON, June 6--An estimated 90 percent of American elms have died, victims of a fungus dating to the 1930's. A new American elm highly tolerant of the fungus-causing Dutch elm disease will be planted June 6 on the grounds of the U.S. Capitol.

At a 9:30 a.m. outdoor ceremony, Congress will take the occasion to honor the research accomplishments of the U.S. National Arboretum in its role as the public gardens of the U.S. Department of Agriculture in Washington. Arboretum scientists developed the new American elm--a tree that once lined city and village streets across the country.

Floyd P. Horn, administrator of USDA's Agricultural Research Service, said the tree to be planted is the newly-named "Valley Forge" elm. It is one of the Arboretum's two new American elms to have unusually high levels of tolerance to the fungus that causes Dutch elm disease. He said the new trees could restore the American elm to the Main Street USA of earlier days.

Congressional recognition of the Arboretum's research contributions over the years, including the new elm, was initiated by Senator Christopher S. Bond of Missouri. Senator Bond, who is an honorary member of the Friends of the National Arboretum, will join USDA and FONA officials at the planting ceremony. They will include Horn, Washington attorney R. Lawrence Coughlin, president of the FONA board of directors and former Congressman from Pennsylvania, Thomas S. Elias, Arboretum director, and Alden M. Townsend, Arboretum researcher of the American elm.

"We are proud that the Congress is paying tribute to the National Arboretum's 68-year history of creating trees, shrubs and plants for landscapes and gardens throughout this country", Horn said.

Elias said that research over the last 20 years by Arboretum plant geneticist Alden M. Townsend produced the two elm varieties. "They will be the first commercially available, Dutch elm-tolerant American elm trees", Elias said.

Over a hundred rooted cuttings of Valley Forge and the other variety, New Harmony, were distributed in the last two years to tree nurseries, experiment stations and arboreta. Elias said wholesale nurseries will propagate the trees for sale by late 1997 or 1998, while retail nurseries should have them in 1999.

Elias said Townsend and colleagues over the years screened thousands of American elms and inoculated the culprit fungus into specimens, eventually narrowing the selection to the final two trees. Townsend first did the research at the Arboretum's former Delaware, Ohio, research site alongside plant pathologist Lawrence R. Schreiber and technician Warren D. Masters. He then continued at the Arboretum's Glenn Dale, Md., laboratory, with horticulturist Susan E. Bentz and gardener Tom Abell.

"We wanted to find American elms that are as adapatable to urban stress as were earlier elms. They were the main landscape tree in cities and towns", Townsend said. "Just about every municipality has an Elm Street."

"Compared with other American elm selections and seedlings, these two new trees had significantly lower foliar symptoms and crown die-back, even after being intensively inoculated with the Dutch elm fungus", Townsend said. "Neither tree is completely immune to the disease, he noted." Valley Forge is the most tolerant, while New Harmony is among the three most tolerant trees the researchers identified.

Elias said USDA scientists originally began screening elm trees for Dutch elm disease tolerance after the disease's onslaught in the 1930's. The fungus that causes the disease was accidentally introduced to the United States in 1931 on elm logs shipped from France, en route to Cleveland, Ohio. By the 1980's, Ophiostoma ulmi--the destructive fungus--had wiped out 77 million American elms.

Until the fungus struck, Elias said, the American elm was a hardy tree. It tolerates air pollution, poor soil and de-icing salt, he said, while offering shade and shape appealing to the eye.

Besides elms, Townsend and Arboretum colleagues work on maples, alders, spruce, hemlock, birch, black gum and several other tree species. In the 68 years since it was established, the Arboretum has introduced more than 645 new landscape trees, shrubs and floral plants for urban, suburban and rural use, Elias said.

Located on 444 acres in northeast Washington, D.C., the Arboretum is open to the public and sponsors a full schedule of educational activities, over and above the research. Thousands of plantings are on display in various gardens and collections on the grounds, including the new National Bonsai and Penjing Museum, the National Herb Garden, azalea gardens, Fern Valley, the Gotelle Dwarf Conifer Collection and special plantings of magnolias, hollies, lilacs, crapemyrtles, dogwoods, Japanese maples and others.

Scientific contact: Thomas S. Elias, U.S. National Arboretum, Agricultural Research Service, USDA, Washington, D.C. 20002; phone (202) 245-4539,; or Alden M. Townsend, U.S. National Arboretum, ARS, USDA, Glenn Dale Laboratory, Glenn Dale, Md. 20769; phone (301) 344-4175.

A fact sheet on each of the two new American elms and Dr. Townsend's research paper on the new trees are available. Color slides also are available.

Planting location on the U.S. Capitol grounds: between Constitution Ave. and Pennsylvania Ave. just east of 3rd St., N.W.

Last Modified: 4/18/2014
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