Genetic testing has determined that a rare type of mustard plant in northern Utah actually is two species, complicating Olympics preparation at Snowbasin resort near Ogden.

Scientists have determined the lime-green plants with yellow flowers, which cling to the craggy terrain where the men's downhill race course will begin, are genetically different from the Maguire mustard (Draba maguirei). The latter plant is found only in northern Utah, in limited numbers, and is listed as a sensitive species by the Forest Service.Because Snowbasin's plants are not related to the Maguire mustards, both species' numbers are smaller than previously estimated. So extra care must be taken to protect the resort's population.

The Forest Service and Sun Valley Corp., owner of the resort, contracted surveys to determine the range and number of the newly described species, and resort personnel have been trained to identify the plant.

Through additional research, the team hopes to clarify what mitigation measures can be implemented to maintain a viable population of the newly identified species, likely to be called Burke mustard (Draba burkei).

There are believed to be 5,000 to 6,000 of the plants at Snowbasin, making it the largest population of the newly described species.

The discovery is not expected to significantly disrupt Snowbasin's preparations for the 2002 Winter Games but could cause some delays.

"It does change things," Ruth Monahan, the Forest Service's Ogden District ranger, said Thursday. "Our hope is that through the mitigation measures we develop, we can complete the . . . projects."

Affected Olympic projects include grading work on the upper slope of the men's downhill course, construction of the start house where racers push off, excavation of a water line for snowmaking and installation of a new ridgetop communications tower. A non-Olympic plan to build a restaurant near the top of the new Strawberry lift also is affected.

The Forest Service has known for some time that small populations of mustard plants existed in northern Utah and that botanists were uncertain whether they represented one species or two.

The uncertainty was eliminated when scientists affiliated with the Utah Museum of Natural History's Garrett Herbarium confirmed through chromosome, enzyme and DNA studies that two species exist.

"The (Burke mustard) seems to be a pretty viable species," said herbarium curator Michael Windham. "But the Forest Service has estimated there are only 10,000 (plants) total. As your population drops and becomes more fragmented, it really represents a threat to the species. We don't want to lose many plants, or we may exceed minimum viability levels."

The Forest Service and U.S. Fish and Wildlife Service have agreed that the loss of up to 500 plants associated with the Olympics projects would not affect the population viability.

Where disturbance cannot be avoided, selective plants will be removed, the Forest Service said. Seed will be collected and stored.

Detailed mapping studies are under way to get a more precise count of mustard-plant population and distribution.