While environmentalists, ranchers, and agencies argue about slickspot peppergrass, researchers uncover another threat to the rare plant.
Slickspot peppergrass knows what it likes. The small plant with white springtime flowers likes southwestern Idaho -- it grows nowhere else. The plant, which is not actually a grass, will live only on certain soils. Within those soils, it only grows in slickspots -- small depressions that hold water longer into the hot, dry summer than the surrounding area.
Despite its narrow definition of a good home, slickspot peppergrass held its own until recently. As Idaho’s population grew and other uses encroached on its limited habitat, the number of plants fell. People who don’t like cattle on public land point to their standard target as the cause. Ranchers point to the monitoring data, which don’t show a link between cattle and the plant’s numbers. Researchers point out that the data only provide once-a-year snapshots, which reveal little about why the plant is declining.
Ian Robertson, an entomologist at Boise State University, studied insect pollinators of the rare plant, which spreads only by seeds. He also noticed insects doing something quite different: ants were harvesting the seeds and carrying them off. I wrote about Ian’s findings for the Boise State Division of Research and Economic Development.