December 2012 Number 1 - Utah Native Plant Society

Calochortiana December 2012 Number 1
RESULTS
Species Richness
Based on our re-examination of herbarium specimens,
review of literature, and new field work, 354 species
and varieties of vascular plants (Table 1) are currently
known from Cedar Breaks National Monument
(Fertig 2009b, Fertig et al. 2009c). At least 74 of these
taxa have been discovered since 2005. Overall, the
monument’s flora has increased by 21% since Roberts
and Jean (1989) reported 277 species for the area. The
Figure 2. National Park Service units and BLMmanaged
national monuments in Utah. Park acronyms:
ARCH (Arches National Park), BRCA (Bryce Canyon
National Park), CANY (Canyonlands National Park),
CARE (Capitol Reef National Park), CEBR (Cedar
Breaks National Monument), DINO (Dinosaur National
Monument), GCNRA (Glen Canyon National Recreation
Area), GOSP (Golden Spike National Historic
Site), GSENM (Grand Staircase-Escalante National
Monument), HOVE (Hovenweep National Monument),
NABR (Natural Bridges National Monument), RABR
(Rainbow Bridge National Monument), TICA
(Timpanogos Cave National Monument), ZION (Zion
National Park). Map courtesy of Zion National Park
Resource Management & Research GIS.
flora of Cedar Breaks contains 9.7% of the 3659 native
and naturalized plant species documented in Utah by
Welsh and others (2008) and 36% of the 156 reported
families.
Native species account for 94.9% of the flora of Cedar
Breaks National Monument (336 species). Nearly
82% of the species range widely across western North
America and are common in Utah (Table 1). Eighteen
taxa are categorized as local endemics that occupy a
total area of less than 16,500 square kilometers and are
restricted to the immediate vicinity of Cedar Breaks or
adjacent high plateaus of south-central Utah (mostly the
Tushar Range and Paunsaugunt Plateau) (Fertig 2009b).
An additional 20 taxa are found only in the Colorado
Plateau area of southern Utah, northeastern Arizona,
northwestern New Mexico, and southwestern Colorado.
Together these 38 local and regional endemics account
for 10.7% of the monument’s flora. Just over 2% of the
flora consists of species that occur sporadically across
Utah (sparse taxa) or have populations in Cedar Breaks
that are widely isolated from their main, contiguous
range (disjunct) (Table 1).
Only 18 introduced species (those not historically
native to Utah or North America) have become established
in the monument, representing 5.1% of the total
flora (Table 1). The percentage of introduced species at
Cedar Breaks is less than half that reported for the entire
flora of Utah (13.5%) (Fertig 2007, Welsh et al.
2008). None of the introduced plant taxa in the monument
are listed by the state of Utah as official noxious
weeds.
Rare Species
The Conservation Data Center (CDC) of the Utah
Division of Wildlife Resources (1998) recognizes 22
species from Cedar Breaks National Monument as species
of concern (Table 2). Most of these are local or
regional endemics restricted to the Claron Formation or
species that are widespread outside of Utah but have 10
or fewer extant populations in the state. We consider
two additional species from the monument to be deserving
of recognition by the CDC. Madsen’s daisy
(Erigeron vagus var. madsenii) is a southern Utah endemic
that was only described as a new taxon in 2008
(Welsh et al. 2008). Rosy cliff jamesia (Jamesia americana
var. rosea) was not recognized as occurring in the
state of Utah until we verified populations in Cedar
Breaks and the Ashdown Gorge Wilderness Area in
2008. Previously, populations of this taxon were
thought to represent var. zionis, a local endemic of
southern Utah listed by the CDC as a species of concern
and by the US Forest Service and BLM as sensitive.
Var. rosea was formerly known only from California
and Nevada (Fertig and Reynolds 2009, Holmgren and
Holmgren 1989). In all, seven species from Cedar
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