Science News 17/04/2014

New ornamental Tung tree available

Anna Bella may herald a new generation of ornamental tung tree varieties suitable for landscape uses in the U.S. Gulf Coast region.

According to U.S. Department of Agriculture (USDA) molecular geneticist Timothy Rinehart, Anna Bella marks a first in ornamental tung releases because it is sterile and produces virtually no nuts, which are toxic if ingested and pose a mowing hazard if left on the ground.

From the late 1920s to early 1970s, tung trees had been grown commercially on plantations across the Gulf Coast area as a nut-based source of high-quality oil for paints, varnishes, lacquers, wood finishes and other industrial products. A convergence of factors ultimately scuttled the tung oil industry there, but nostalgia for Vernicia fordii, as the native Chinese tree is known scientifically, has lingered to this day.

The downside to planting tung as an ornamental has been the nuts, which are no longer harvested for their oil, notes Rinehart, with the Thad Cochran Southern Horticultural Research Laboratory operated in Poplarville, Miss., by the Agricultural Research Service (ARS). ARS is USDA's chief intramural scientific research agency.

Anna Bella, which is adapted to conditions in the South, can reach nearly 40 feet tall and opens into an umbrella-shaped canopy of lush, heart-shaped leaves. It blooms in late spring, producing clusters of white, long-lasting flowers tinged in the centers with yellow or red. The new variety requires little maintenance, bounces back well from pruning, and can withstand common insect pests and diseases.

It is ideal for both single specimen and row plantings, such as in backyards and along roadsides or property boundaries. Because it produces no seed, the variety is unlikely to persist beyond intended planting sites, a characteristic that may encourage wider acceptance of the tree species as an ornamental offering.

Rinehart has already received requests from a few specialty nurseries interested in propagating the variety.

di S. C.