An unapproved type of genetically engineered grass has been found growing in the wild in what scientists say could be the first instance in the United States in which a biotechnology plant has established itself outside a farm. Ecologists at the Environmental Protection Agency said they had found a small number of the grass plants growing in central Oregon near the site of field tests that took place a few years ago. The EPA scientists and others said the grass would probably not pose an ecological threat. Still, it could provide fodder for critics who say that agricultural biotechnology cannot be adequately controlled. "It is a cautionary tale that you have to think about the possibility of plants escaping into populations where there are wild relatives present,' said Jay Reichman, an agency ecologist who is the lead author of a study to be published in the journal Molecular Ecology. The genetically engineered grass, called creeping bentgrass,is being developed by the Scotts Miracle-Gro Company and Monsanto for use on golf courses. It contains a bacterial gene that makes the grass resistant to the herbicide Roundup, known generically as glyphosate.