Amargosa Niterwort

Nitrophila mohavensis

Description

Amargosa niterwort, Nitrophila mohavensis, is a long-lived, low-growing, perennial, 3.3 in (8.4 cm) tall, with bright-green, succulent leaves arranged in densely overlapping tiers along each stem. It bears tiny, inconspicuous flowers.

Habitat

Amargosa niterwort grows in scattered sinks that are fed by outflows from saline and alkaline springs. The springs originate to the north and east in Ash Meadows, which is a unique wetlands habitat in the heart of the Mohave (Amargosa) Desert. The water that supplies this constant, natural irrigation, was stored in a fossil aquifer more than 10,000 years ago and is discharged through an extensive underground drainage system. Ash Meadows boasts many endemics, which depend upon the wetlands for survival. The Amargosa niterwort is a peripheral associate of this plant community.

Distribution

Amargosa niterwort is found at very localized sites where suitable habitat occurs in eastern Inyo County, California, and southern Nye County, Nevada. It is known from only two sites about 4 mi (6.4 km) miles apart, where the Carson Slough flows south from Nevada into California. The niterwort has the most restricted range of any plant endemic to the Ash Meadows area and survives in very low numbers.

Threats

A significant portion of niterwort habitat was eliminated in the 1960s when the Carson Slough was drained for peat mining, thus lowering the water table and shrinking seepage zones. Afterwards, nearby fields were plowed for agriculture, interrupting free-flowing water into the habitat. Subsequent groundwater pumping for irrigation reduced spring flows.

The Nevada population lies in a remote area where the disturbance has been limited to trampling by wild horses and soil compaction by off-road vehicles.

Conservation and Recovery

Critical Habitat for the niterwort was designated to include 1,200 acres (485.6 hectares) in Inyo County, California, encompassing the surviving populations and allowing for future expansion. Amargosa niterwort was listed as Endangered, rather than Threatened, because none of its Critical Habitat falls within the protective confines of the Ash Meadows National Wildlife Refuge.

Both known populations grow on land managed by the Bureau of Land Management (BLM). Future activities that may affect the species, such as granting permits for livestock grazing or mineral exploration, will trigger consultations between the BLM and the Fish and Wildlife Service to consider the welfare of the species.

Contact

U. S. Fish and Wildlife Service
Regional Office of Endangered Species
911 N. S. 11th Ave.
Portland, Oregon 97232

References

Munz, P. A., and J. C. Roos. 1955. "California Miscellany III." Aliso 3:112-114.

Reveal, J. L. 1978. "Status Report on Nitrophila mohavensis Munz and Roos (Amargosa Niterwort)." Report. Department of the Interior, Washington D.C.