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Home/Species/ Maguire's Primrose

Primula maguirei

L.O. Williams

Maguire's Primrose

G1Critically Imperiled Found in 13 roadless areas NatureServe Explorer →
G1Critically ImperiledGlobal Rank
Very highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.143121
Element CodePDPRI080B0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderPrimulales
FamilyPrimulaceae
GenusPrimula
Synonyms
Primula cusickiana var. maguirei(L.O. Williams) N. Holmgren & S. Kelso
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
Holmgren (2005) and FNA (vol. 8, 2009) reduce Primula maguirei (= P. cusickiana var. maguirei) to varietal status under P. cusickiana.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-03-07
Change Date1991-04-02
Edition Date2023-03-07
Edition AuthorsRoth, E., rev. B. Franklin/K. Maybury (1996), rev. A. Treher (2011), rev. Eberly (2023)
Threat ImpactVery high
Range Extent<100 square km (less than about 40 square miles)
Number of Occurrences6 - 20
Rank Reasons
Primula maguirei is a narrow endemic of Logan Canyon in Cache County, Utah, U.S.A. Primula maguirei is most limited by the availability of suitable habitat (dolomitic cliffs and boulders with cool, moist microclimate). Rock climbing, mountains goats, and possibly prolonged drought are the primary threats to this species.
Range Extent Comments
Primula maguirei occurs in the western United States and is endemic to the Logan Canyon in Cache County, Utah, where it inhabits a 10 mile stretch of the Upper and Lower Canyons (Tilley et al. 2011, USFWS 2021).
Occurrences Comments
There are 6 known occurrences (Tilley et al. 2011), separated by one kilometer (Utah Natural Heritage Program 2021).
Threat Impact Comments
Wild collecting, rock climbing, and other recreational activities are ongoing threats (England 1990, Tilley et al. 2011). The USU Logan Canyon Climbing Management Plan for the Uinta-Wasatch-Cache National Forest, Logan Ranger District (2017) specifically addressed management in relation to climbing and increasing public awareness as well as outreach to climbing community has greatly reduced the threat to this species in regards to climbing (Utah Natural Heritage Program 2021). Introduction of mountain goats may also threaten this species (USFWS 2021). In addition, prolonged drought may be a threat. Road construction is no longer a threat to the species (USFWS 2021) but the status of water line development is unknown.
Ecology & Habitat

Description

Small perennial with showy rosey lavender flowers and bright green basal leaves.

Diagnostic Characteristics

Similar to other Primula species but differs in having the calyx 5.5-7.5 mm long (to 9 mm long in fruit), and obovate corolla lobes 4-5 mm wide.

Habitat

This species occurs on damp ledges, crevices, and over-hanging rocks along canyon walls. Site are almost always on north-facing, moss covered limestone cliffs at or near the canyon bottom in shallow dolomitic soils of the Laketown and Fish Haven geologic formations (Tilley et al. 2011). It grows at elevations of 1,350 to 1,700 m elevation.

Ecology

Plant associates include Pink Alumroot (Huechera rubescens), Mat Rockspirea (Petrophytum caespitosum), Tadpole Buttercup (Ranunculus ranunclulinus), and Narrowleaf Wildparsley (Musineon lineare) (Tilley et al. 2011).

Reproduction

This species flowers mid-April to mid-May and seeds disperse from May to June (England 1990). It reproduces sexually, resulting in best seed production, and asexually, through rhizomatous roots which support multiple stems per plant (USFWS 2021).
Terrestrial Habitats
Bare rock/talus/screeCliff
Other Nations (1)
United StatesN1
ProvinceRankNative
UtahS2Yes
Threat Assessments
ThreatScopeSeverityTiming
4 - Transportation & service corridorsLarge - restrictedModerate or 11-30% pop. declineInsignificant/negligible or past
4.1 - Roads & railroadsLarge - restrictedModerate or 11-30% pop. declineInsignificant/negligible or past
5 - Biological resource useRestricted (11-30%)Slight or 1-10% pop. declineHigh (continuing)
5.2 - Gathering terrestrial plantsRestricted (11-30%)Slight or 1-10% pop. declineHigh (continuing)
6 - Human intrusions & disturbancePervasive (71-100%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesPervasive (71-100%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesPervasive (71-100%)Extreme - moderateHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesPervasive (71-100%)Extreme - moderateHigh (continuing)
8.1.2 - Named speciesPervasive (71-100%)Extreme - moderateHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.2 - DroughtsPervasive (71-100%)UnknownHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (13)
South Dakota (1)
AreaForestAcres
Indian CreekBuffalo Gap National Grassland24,666
Utah (12)
AreaForestAcres
Boulder MountainWasatch-Cache National Forest8,852
Mahogany RangeWasatch-Cache National Forest11,409
Mt. Logan NorthWasatch-Cache National Forest18,930
Mt. Logan NorthWasatch-Cache National Forest18,930
Mt. Logan SouthWasatch-Cache National Forest17,014
Mt. Logan SouthWasatch-Cache National Forest17,014
Mt. Logan WestWasatch-Cache National Forest5,285
Mt. NaomiWasatch-Cache National Forest41,922
Mt. NaomiWasatch-Cache National Forest41,922
Right Hand Fork LoganWasatch-Cache National Forest15,023
Right Hand Fork LoganWasatch-Cache National Forest15,023
Temple PeakWasatch-Cache National Forest24,081
References (8)
  1. England, J.L. 1990. Maguire primrose (<i>Primula maguirei</i>) recovery plan. U.S. Fish and Wildlife Service, Denver, Colorado. 13 pp.
  2. Flora of North America Editorial Committee (FNA). 2009. Flora of North America north of Mexico. Vol. 8. Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press, New York. xxiv + 585 pp.
  3. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  4. Tilley, D., L. St. John, and D. Ogle. 2011. Plant guide for Maguire's primrose (<i>Primula cusickiana </i>var<i>. maguirei</i>). USDA-Natural Resources Conservation Service, Idaho Plant Materials Center. Aberdeen, Idaho.
  5. U.S. Fish and Wildlife Service (USFWS). 1985. Final rule to determine <i>Primula maguirei</i> (Maguire primrose) to be a threatened species. Federal Register 50(162): 33731-33734.
  6. U.S. Fish and Wildlife Service (USFWS). 2021. Maguire primrose (<i>Primula maguirei</i>) 5-Year Review. U.S. Fish and Wildlife Service (USFWS). U.S. Fish and Wildlife Service, Utah Ecological Services Field Office.
  7. Utah Natural Heritage Program. 2021. Utah Rare Plant Database (accessed 2021).
  8. Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins (eds.) 1993. A Utah flora. 2nd edition. Brigham Young Univ., Provo, Utah. 986 pp.