December 2012 Number 1 - Utah Native Plant Society

Utah Native Plant Society
Meadows Road, as well as just north of Devils Hole
Road in the Collins Ranch area, east of Crystal Reservoir
and between the south end of Lower Crystal Marsh
and the Refuge boundary. Due to a short bloom time,
several occurrences west of the Refuge office were not
surveyed in 2008. The total estimated population at this
time is 376,632 individuals, a number that will likely
increase upon completion of surveys.
Ash Meadows Ivesia (Ivesia kingii): Endemic to the
Refuge, Ash Meadows ivesia is a federally-listed threatened
species. It is a perennial plant with a prostrate
growth form. As is the case with many of the endemic
Refuge plants, there is little current information regarding
its abundance. According to the USFWS, the distribution
of this species is limited to Nye County, Nevada,
and likely limited to within AMNWR boundaries. Population
estimates by the NNHP in the 1980s indicated
there were as many as nine occurrences; these areas
contained an estimated 3,862 individuals (Morefield
2001).
The majority of the 2008 surveys confirmed populations
occurring within historic distribution areas on the
Refuge. However, field crew members were unable to
locate plants within several previously documented areas
believed to contain populations and extant populations
appeared significantly smaller. However, a visit in
the Jackrabbit Spring area led to the discovery of several
new populations. New populations, fairly large in size,
were also surveyed in close proximity to West Spring
Meadows Road where it makes a sharp turn to the west.
Also, multiple, substantial populations were located and
surveyed between Crystal Reservoir and West Spring
Meadows Road. Another population was documented in
a seepage area interrupting an upland habitat just east of
the Cold Spring private property. Finally, populations
occurring just north and south of Big Springs Road were
surveyed. The current estimated population of Ash
Meadows ivesia is 486,798 individuals (Table 3).
Ash Meadows Blazingstar (Mentzelia leucophylla):
This endemic biennial herb was listed as a threatened
species in 1985. The plant’s distribution appears to be
strictly limited to areas within the Refuge (Morefield
2001; Otis Bay and Stevens Ecological Consulting
2006). Recent information regarding species abundance
is limited. Surveys in 1986 documented M. leucophylla
from 8 locations with an estimated population of 358
individuals (Morefield 2001). Distribution maps provided
by the Refuge from 2006 internal surveys show
confirmed populations at Purgatory, the Warm Springs
Complex, and along West Spring Meadows Road.
Additional populations of Ash Meadows blazingstar
were discovered during surveys for Ash Meadows sunray
and Ash Meadows milkvetch. Because of its biennial
life form, M. leucophhylla was observed in rosette
as well as in flower. Starting in mid-March, BIOWEST
field crews began recording populations south of Peterson
Road near the Cold Spring private property boundary.
In addition, new blazingstar populations were documented
just south of Rogers Spring and west of Longstreet
Road, intermixed with a large white bearpoppy
population southeast of the Warm Springs Complex access
road and directly north of the “T” junction of South
Spring Meadows Road and West Spring Meadows
Road. These populations were surveyed and their
boundaries extended. The estimated population is 3,763
individuals (Table 3).
Blue-Eyed Grass Species (Sisyrinchium species):
Previously, three species of blue-eyed grass were
thought to occur at the Refuge: Death Valley blue-eyed
grass (Sisyrinchium funereum), Nevada blue-eyed grass
(S. halophilum), and St. George blue-eyed grass (S.
radicatum) (C. Baldino 2007 pers. comm.). However,
Cholewa (in letter, 2003) suggested that S. halophilum
probably does not extend as far south as the refuge. She
based her statement on the discovery that many herbarium
specimens that had been identified as that species
were incorrect. Blue-eyed grass species are extremely
difficult to differentiate, so there is ongoing debate and
confusion as to exactly which species actually exist on
the Refuge.
Such problems are not new in Sisyrinchium. Specieslevel
taxonomy of Sisyrinchium has long been disputed.
Recent molecular work has clarified the limits of the
genus and helped identify important morphological
characters delineating it from closely related genera
(Karst, unpublished). However, much more phylogenetic
work, based on cladistic analysis of molecular
data, is needed to understand species relationships
within the genus (Cholewa and Henderson 2002).
Species of Sisyrinchium are not easily distinguished.
White flowers may occur in otherwise blue-flowered
species, and vivipary occasionally occurs, where plants
produce seeds that germinate before they detach from
the parent. Furthermore, vegetative characteristics,
while distinctive in some species, may overlap greatly in
wide-ranging species. Writers of past floras sometimes
were unaware of such phenotypic plasticity, or were
inconsistent in their use of terminology. Some taxonomists
have thought differences too subtle and chosen to
lump species (Cholewa and Henderson 1984, 2002).
Because of the taxonomic confusion surrounding the
blue-eyed grass plants growing within refuge boundaries,
the BIO-WEST 2008 field surveys combined all
occurrences of blue-eyed grass into a Sisyrinchium spp.
category.
As documented by Cholewa and Henderson (2002),
Sisyrinchium funereum populations occur mostly within
Death Valley. These populations contain numerous individuals.
Sisyrinchium radicatum is more widely distributed,
growing in Clark, Nye, and Lincoln Counties,
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