December 2012 Number 1 - Utah Native Plant Society

Calochortiana December 2012 Number 1
tions mentioned in the five-year review were the only
populations known to occur on the Refuge at that time.
Surveys conducted during 2008 extended the
boundaries of the two known populations and added
new occurrences. Some new populations were surveyed
in the area just north of the outflow canal of Crystal
Reservoir. In addition, occurrences noted during the
2007 reconnaissance that were scattered across the west
shore of Lower Marsh were resurveyed as well as populations
found southwest of Crystal Reservoir. These areas
included the drainage from Crystal Reservoir just
north of the Refuge boundary and the Big Spring and
Jackrabbit Spring drainage complex toward the western
Refuge boundary. Also, a portion of critical habitat located
in the west corner of the Refuge directly west of
the Lower Marsh access road was mapped and inventoried.
This population is referred to as the “Central
Carson Slough” population by USFWS (2007b). The
population was mapped in its entirety, including portions
that fell just outside the Refuge boundary, and the
entire population estimate for this polygon was included
in the 2008 total.
White Bearpoppy (Arctomecon merriamii): White
bearpoppy is a Mohave Desert endemic known from
Clark, Lincoln, and Nye Counties in Nevada, and from
the Death Valley region of California. This species occurs
in salt desert shrub communities on ridges, rocky
slopes, gravelly canyon washes, and old lakebeds de-
rived from carbonate rock sources, often in hard clay
soils or with shadscale saltbush. It is a clump-forming
perennial plant with large white flowers borne individually
on the tips of leafless stems. A. merriamii can be
distinguished from the golden-flowered Las Vegas bearpoppy
(A. californica) by its scapose stems, larger capsules,
and flower color.
The NNHP rare plant fact sheet states that there have
been approximately 129 occurrences documented
throughout its Mojave Desert range. The estimated
range-wide population is > 20,000 individuals (Morefield
2001) (Table 3). While there is no documented
evidence of the number of known individuals within the
Refuge prior to this study, it is believed that the distribution
has remained limited with low abundance of individuals
(H. Hundt, AMNWR, 2007, pers. comm.).
Field crews conducted reconnaissance in areas of
potential habitat for this species between 2,000 and
6,200 feet in elevation and within Salt Desert Scrub
communities on alluvial gravel substrates. These areas
included the northernmost portion of the Refuge just
north and south of the Invite Road, the area surrounding
Devils Hole, the alluvial fans surrounding Point of
Rocks, and the extreme southeast corner of the Refuge.
No plants were found during these searches. However,
several previously undocumented populations were discovered
and surveyed throughout the 2008 field season.
These included the area just south of Peterson Road
Table 3. Population estimates for surveyed plant species at Ash Meadows NWR.
Scientific Name Common Name Most Recent Population
Estimate
85
2008 Survey Population
Estimate AMNWR
Arctomecon merriamii White bearpoppy 20,000* 193
Astragalus phoenix Ash Meadows milkvetch 1800 11,643
Calochortus striatus Alkali mariposa lily unknown 6984
Centaurium namophilum Spring-loving centaury 4290* 4,468,571
Cordylanthus tecopensis Tecopa bird’s-beak 4379* 829,918
Enceliopsis nudicaulis var.
corrugata
Ash Meadows sunray 1849 50,954
Grindela fraxinopratensis Ash Meadows gumplant 81,000 376,632
Ivesia kingii var. eremica Ash Meadows ivesia 3862 486,798
Mentzelia leucophylla Ash Meadows blazingstar 358 3763
Nitrophila mohavensis Amargosa niterwort 10,050 78,406
Sisyrinchium spp.* Blue-eyed grass unknown 99,822
Spiranthes infernalis Ash Meadows ladies-tresses 1107 14,209
* Range-wide estimate