The Eureka Valley evening-primrose at Death Valley National Park has been removed from the Endangered Species List/USFWS

Forty years after the Eureka Valley evening-primrose and Eureka dune grass at Death Valley National Park's Eureka Dunes were listed as endangered species under the Endangered Species Act, the evening-primrose has been removed entirely from the list while the dune grass has been down-listed to threatened.

According to the U.S. Fish and Wildlife Service, better management of the dune area, including the reduction of "significant threats" from off-highway vehicles, helped the plants rebound in number. These final determinations were made by the Service after reviewing information obtained through a long-term rangewide monitoring effort, peer review comments, and other data and information.

"We are pleased to showcase successful recovery of two more endangered species in California with the delisting of Eureka Dunes evening-primrose and reclassification of the dune grass to threatened," said Paul Souza, director of the Service's Pacific Southwest Region. "We have an outstanding partnership with Death Valley National Park and applaud their efforts to conserve both these plants and a host of other species that call the park home."

The Eureka Dunes were initially managed by the Bureau of Land Management, which closed off-road vehicle use in 1976. Other management actions taken by BLM included increased ranger patrols, monitoring and environmental education. In 1994, the passage of the California Desert Protection Act transferred the land to the National Park Service as part of Death Valley National Park. The portion of the Park where the plants are found is now designated as a wilderness area, and impacts to the plants from off-road vehicles have been virtually eliminated. The park has taken additional management actions as part of its ongoing efforts to conserve Eureka dune species.

"These plants only live on two dune fields in northern Death Valley National Park," said Death Valley Superintendent Mike Reynolds. "It's an exciting success story that both species are in less danger of extinction than they were a few decades ago. This is due to things like wilderness protection, moving designated campsites away from the plants' habitat, and adding signs to explain how to recreate at Eureka Dunes without harming the unique plants."

In a proposed rule published in February 2014, the Service initially proposed delisting both plants based on recovery. Although the primary threat to Eureka dune grass has been removed, monitoring results indicate that the largest population of dune grass is slowly declining. It is also experiencing very low levels of germination, which may impact the overall health and sustainability of the plant. As such, the plant currently meets the definition of threatened, under the ESA, meaning that it could be come endangered within all or a significant portion of its range in the foreseeable future.

Eureka dune grass is the only member of Swallenia, a monotypic genus (genus containing only one single species). The plants have coarse, stiff stems that reach 20 inches in height, and have sharp-pointed leaves. Eureka dune grass goes dormant during the winter, begins to produce new shoots around February, and flowers starting in April. The flowers of Eureka dune grass are wind-pollinated and do not rely on insect pollinators. Germination and establishment of new plants is an uncommon event, but once established, hummocks can live to be decades old. 

Eureka Valley evening-primrose is a perennial. It produces clusters of flowers that are white fading-to-pink. Flowers appear through the spring and summer months as long as conditions are favorable. This species of evening primrose is pollinated by hawkmoths, butterflies, and bees.