U.S. Geological Survey
On a fine early spring day, the sea of yellow thrown by the blooms of lesser celandine, a cousin of the buttercup, may look lovely to the eyes, but for the National Park service and the U.S. Geological Survey, seeing the extent of the uninvited, invasive plants is a travesty.
What should be visible along the floodplains of Rock Creek in Washington, D.C., is a mix of native spring plants, not this intruder from Western Europe. But how do you remove hundreds of acres of such plants without harming the native species? USGS scientists from the Patuxent Wildlife Research Center are teaming up with NPS resource management staff at Rock Creek Park to pin down the best method to yield maximum control of this non-native plant with minimal impact to the rest of the environment. Because lesser celandine is one of the few plants that show a green face early in the season, researchers took the February window of opportunity to "hit" it with a short-lived herbicide called Rodeo that, under this circumstance, provides minimal risk to desirable native plants. Though scientists realize that biological controls have their advantages, the likelihood of finding agents that would target only this member of the large buttercup family is small and would be full of risk to the native buttercups. It is a daunting and humbling task to be faced with controlling a large mass of reproducing vegetation that must be dealt with selectively. But the watchword of invasive plant management is perseverance, meaning that one-time treatment will not be successful. It is the intent of USGS and NPS that the amount of energy and funding expended each year on controlling lesser celandine will be reduced through less extensive followup treatments and that native Spring plants will flourish once again in the floodplains of Rock Creek Park.