T. Edward Nickens, National Wildlife 

Botanists are teaming up with law enforcement officers to crack down on the booming illegal trade in wild herbs.

Thunder grumbles over Cataloochee Divide, a 5,000-foot-tall ridge that snakes over the northeast corner of the Great Smoky Mountains National Park in North Carolina. Squatting at the base of a towering silverbell tree, Jim Corbin shakes his head sheepishly. As a plant protection specialist with the North Carolina Department of Agriculture, Corbin spends countless days in the deep woods of the southern Appalachians; he knows better than to leave his rain gear in the car. The first fat raindrops splat on a dense canopy of tulip poplar, red maple and black cherry trees, then drip onto a diverse understory of shrubs and flowers: black cohosh, New York fern, Solomon's seal, Jack-in-the- pulpit, bloodroot, speckled wood lily and Dutchman's pipe. And the coveted plant that Corbin holds between two dirt-stained fingers: American ginseng.

Corbin expertly scrapes dirt from the plant's stem, exposing a gnarly, carrotlike root. He sprays it with two quick blasts from a can of aerosol drying agent, then pulls out a small pill bottle. Two taps of his left index finger is all it takes: A fine orange powder, bright as a hunter's safety hat, spills out of the bottle and onto the ginseng root. Corbin replaces the loamy soil and lightly tamps it down with his palm. "That's it," he says. "That plant is marked for a lifetime."

Marked and safe, Corbin hopes. Selling for $270 to $600 per dried pound of root, wild ginseng is one of the most sought- after species in an exploding international market for native plants. (See box at end of story.) And it's the poster child for an interagency push to stymie the illegal poaching of those plants from public lands. Across the country, botanists are teaming up with law enforcement officers to attach sophisticated marking devices, both hidden and visible, to highly prized wild plants.