CPC Plant Profile: Eureka Dunegrass
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Plant Profile

Eureka Dunegrass (Swallenia alexandrae)

This shot shows plants in their habitat. Photo Credit: Walter Wisura
Description
  • Global Rank: G2 - Imperiled
  • Legal Status: Federally Threatened
  • Family: Poaceae
  • State: CA
  • Nature Serve ID: 142060
  • Date Inducted in National Collection: 02/10/1987

Swallenia alexandrae is a perennial grass found only in the southern portion of Eureka Valley Sand Dunes system in Inyo County, California (USFWS 1983). The grass forms large clumps across dune slopes and spreads as the shifting sand surrounds newly formed stems. Flowering stalks are 1.5 to 10 dm tall and have stiff lance like blades that are 2.5 to 12cm in length (USFWS 1983). Small flowers grow in narrow clusters and bloom from April to June (Munz 1974). Since the Dune Grass was discovered in 1949 by Anne Alexander, it's populations have been in decline as a result of off road vehicle recreation (USFWS 1983). In 1976, The Bureau of Land Management closed the Dunes to vehicle recreation (USFWS 1983). Although this has promoted recovery, plants are still threatened because closure to off road vehicles is not fully observed. Swallenia alexandrae was federally listed as an endangered species on April 26, 1978.

Participating Institutions
Updates
  • 09/01/2020
  • Orthodox Seed Banking

Based on an September 2020 extract of the California Plant Rescue Database, California Botanic Garden holds 2 accessions of Swallenia alexandrae in orthodox seed collection. There are as many as 3171 seeds of this species in their collection - although some may have been used for curation testing or sent to back up.

  • 08/05/2020
  • Seed Collection

Based on an August 2020 extract of the California Plant Rescue Database, California Botanic Garden has collected 1 seed accessions of Swallenia alexandrae from 1 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass an unknown number of maternal plants

Nature Serve Biotics
  • 05/02/2017

Endemic to Inyo County, California, Swallenia alexandrae is known from only five occurrences on the desert dunes in Death Valley National Park. Although vehicular traffic is prohibited, vehicular trespass and recreational campers still pose threats to this taxon. Its desert dune habitat is extremely fragile.

  • 01/01/2010

Since the 1960's, the Dunes have become a popular place for recreational four wheel driving (USFWS 1977). Although the Dunes were closed to vehicular activity in 1976, illegal activity continues. The spinning of wheels through the sand cuts grass rhizomes

  • 01/01/2010

Size and occurrences of populations are largely unknown.

  • 01/01/2010

Research by Pavlik and Barbour (1988) has shown that data for seed production, survivorship, seed bank and seed establishment may aid in designing a monitoring program for rare plants in Eureka Dunes, California. The authors found that the endemic populations of Swallenia, Oenothera and Astragalus at the dunes are not declining. Although the plant populations appear to be stable further study is warranted on the pollinator populations.

  • 01/01/2010

The primary objective of the Eureka Valley Dunes Recovery Plan is to protect the existing dunegrass and associated species from human threats. There is no plan for transplantation or other methods of propagation to support existing populations (USFWS 1983). The plan does call for adequate monitoring of remaining populations.

  • 01/01/2010

Population monitoring and understanding of reproductive biology is needed in order to aid conservation efforts.

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Photos
Nomenclature
Taxon Swallenia alexandrae
Authority (Swallen) Soderstrom & Decker
Family Poaceae
CPC Number 4171
ITIS 42201
USDA SWAL
Common Names Eureka Dunes grass | Eureka Valley dunegrass | Eureka dunegrass
Associated Scientific Names Swallenia alexandrae | Ectosperma alexandrae
Distribution Swallenia alexandrae is endemic to the Eureka Dunes, located in Eureka Valley in eastern Inyo County, California. Eureka Valley is northwest of Death Valley and is bordered by the Inyo Mountains to th
State Rank
State State Rank
California S2
Habitat

Swallenia alexandrae is restricted to sandy slopes in the Eureka Valley Dunes system.

Ecological Relationships

The blue-green weevil is restricted to the Eureka Dunes and can survive because of the shade provided by Swallenia alexandrae (California Department of Fish and Game 1988). Associated plant species include the Eureka Evening Primrose (Oenothera avita ssp. eurekensis) and the Eureka locoweed (Astragalus lentiginosus var. micans, both are regarded as endangered (USFWS 1978).

Pollinators
Common Name Name in Text Association Type Source InteractionID

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