Home/Species/ Navajo Sedge

Carex specuicola

J.T. Howell

Navajo Sedge

G2Imperiled (G2G3) Found in 12 roadless areas NatureServe Explorer →

G2ImperiledGlobal Rank

Very high - highThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.131813

Element CodePMCYP03CQ0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

Endemicendemic to a single nation

KingdomPlantae

PhylumAnthophyta

ClassMonocotyledoneae

OrderCyperales

FamilyCyperaceae

GenusCarex

Other Common Names

Navajo sedge (EN)

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

Analysis of newly collected specimens by Reznicek and Murray (2013) find Carex specuicola to be supported as a distinct species, as recognized by Murray in FNA (2002, vol. 23) and in Kartesz (1994, 1999).

Conservation Status

Rank Method Rank calculation - Biotics v2

Review Date2023-02-09

Change Date2023-02-09

Edition Date2022-09-09

Edition AuthorsRoth, E., rev. Schwartz/Maybury (1996), rev. Treher (2022)

Threat ImpactVery high - high

Range Extent5000-20,000 square km (about 2000-8000 square miles)

Number of Occurrences21 - 300

Rank Reasons

Carex specuicola is a perennial sedge of the western United States that is endemic to Arizona and Utah and primarily occurs on lands managed by the Navajo Nation. It is restricted to hanging gardens, a seepage habitat that relies upon perched aquifers. The greatest threat to this species is aquifer depletion due to long-term drought related to climate change. Some occurrences might be threatened by invasive species, but more monitoring may be needed to understand this potential threat. Many occurrences are on cliffs which protects them from grazing and water diversion.

Range Extent Comments

Carex specuicola occurs in the southwestern United States, where it occurs in Arizona in Coconino, Apache and Navajo counties and Utah in San Juan County. Range Extent was estimated at roughly 19,000 sq km using a minimum convex hull polygon drawn around occurrences (NatureServe 2022, SEINet 2022).

Occurrences Comments

Using a 1 km separation distance, there are 64 occurrences (USFWS 2019) composed of 160 sites. Due to our limited understanding of population dynamics, the rhizomatous nature of the plants, and the isolated nature of each hanging garden , it may be more appropriate to delineate by hanging garden instead of a standard distance, which would equate to over 160 occurrences (G. Rink, pers. comm., 2022, USFWS 2019).

Threat Impact Comments

The greatest threat to this species is aquifer depletion due to long-term drought related to climate change. Livestock are present at around six sites but are not documented to cause plant mortality, only damage (USFWS 2019), and that damage has been shown to not be long-term. The interpretation of the threat of livestock was largely eliminated. At one site with extreme grazing, plants have recovered (Rink and Hazelton 2014). Invasive species, including Phragmites australis, are documented at some sites and might pose a threat, but monitoring is needed to determine if those possible threats exist (Nora Talkington, pers. comm., 2022). Plants are often on cliffs where they are protected from livestock (G. Rink, pers. comm. 2022, Nora Talkington, pers. comm., 2022).

Ecology & Habitat

Habitat

This species grows in hanging gardens (cliff associated springs), in alcoves in rock faces with no soil or somewhat limited soil development (G. Rink, pers. comm., 2022, Rink and Licher 2015). It grows at elevations of 1,490 to 2,300 m elevation (Rink and Licher 2015). This species was thought to be restricted to Navajo sandstone, but it is now known to occur on Cedar Mesa, De Chelly, Kayenta, and Wingate geologic formations (USFWS 2019).

Reproduction

The species spreads, primarily, through rhizomes, creating thick mats (USFWS 2014). However, an genomic analysis showed that dispersal and colonization is likely occurring (Chapin et al. 2022).

Terrestrial Habitats

Cliff

Other Nations (1)

United StatesN2

Province	Rank	Native
Utah	S1	Yes
Navajo Nation	S2	Yes
Arizona	S2	Yes

Threat Assessments

Threat	Scope	Severity	Timing
2 - Agriculture & aquaculture	Negligible (<1%)	Slight or 1-10% pop. decline	High - low
2.3 - Livestock farming & ranching	Negligible (<1%)	Slight or 1-10% pop. decline	High - low
7 - Natural system modifications	Negligible (<1%)	Unknown	High - low
7.2 - Dams & water management/use	Negligible (<1%)	Unknown	High - low
8 - Invasive & other problematic species, genes & diseases	Negligible (<1%)	Unknown	High - low
8.1 - Invasive non-native/alien species/diseases	Negligible (<1%)	Unknown	High - low
8.1.1 - Unspecified species	Negligible (<1%)	Unknown	High - low
11 - Climate change & severe weather	Pervasive (71-100%)	Extreme - serious	High (continuing)
11.2 - Droughts	Pervasive (71-100%)	Extreme - serious	High (continuing)

Plant Characteristics

DurationPERENNIAL

Economic Value (Genus)No

Roadless Areas (12)

South Dakota (1)

Area	Forest	Acres
Indian Creek	Buffalo Gap National Grassland	24,666

Utah (11)

Area	Forest	Acres
Boulder Mtn. / Boulder Top / Deer Lake	Dixie National Forest	110,690
Box - Death Hollow	Dixie National Forest	3,175
Capital Reef	Dixie National Forest	763
Happy Valley	Dixie National Forest	14,458
Horse Mountain - Mans Peak	Manti-Lasal National Forest	22,159
Long Neck Mesa / Steep Creek / Oak Creek - Steep Creek / Oak	Dixie National Forest	55,489
Lookout Peak	Fishlake National Forest	9,195
Mcgath Lake - Auger Hole	Dixie National Forest	8,334
New Home Bench	Dixie National Forest	10,513
Thousand Lake Mountain	Fishlake National Forest	27,267
Wayne Wonderland	Fishlake National Forest	12,395

References (20)

Chapin, K.J., M.R. Jones, D.E. Winkler, G. Rink, and R. Massatti. 2022. Evolutionary dynamics inform management interventions of a hanging garden obligate, Carex specuicola. Frontiers in Conservation Science 3.
Flora of North America Editorial Committee (FNA). 2002b. Flora of North America north of Mexico. Vol. 23. Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford Univ. Press, New York. xxiv + 608 pp.
Howell, J.T. 1949. Three new Arizona plants. Leaflets of Western Botany 5(9): 148-15149.
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.
Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
NatureServe. 2022. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
Phillips, A.M., III. 1981. Status report. Carex specuicola. J.T. Howell. Submitted to: Office of Endangered Species, the U.S. Fish and Wildlife Service, Albuquerque, New Mexico.
Reznicek, A., and D. Murray. 2013. A re-evaluation of Carex specuicola and the Carex parryana complex (Cyperaceae). Journal of the Botanical Research Institute of Texas 7(1): 37-51.
Rink, G. 2016. Survey for Carex specuicola, Navajo sedge, in support of the Draft Recovery Plan Fall, 2016 Section 6 Report. Reference No. 2015-2017-07.
Rink, G., and A. Hazelton. 2014. Demography Studies for Carex specuicola (Navajo sedge, Cyperaceae). 2014 section 6 final report for the U.S. Fish and Wildlife Service. Reference No. 2013-2014-07.
Rink, G., and M. Licher. 2015. Vascular Plants of Arizona: Cyperaceae Sedge Family Part 1: Family Description, Key to the Genera, and Carex L. Canotia 11: 1-97.
Rink, Glenn. Personal Communication. Botanist. Far Out Botany, Flagstaff, Arizona.
Roth, Daniela. October 17, 1998. Personal communication to Martha Martinez through electronic mail: plants endemic or mostly ocurring in Navajo Nation lands. Botanist for the Navajo Nation Heritage Program.
Rutman, S. 1992. Our unique Arizona flora: Carex specuicola (Navajo sedge). The Plant Press 16(2): 8.
Southwest Environmental Information Network (SEINet). 2022. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2022).
Talkington, Nora. Personal Communication. Navajo Natural Heritage Botanist, Navajo Natural Heritage Program, Navajo Nation Department of Fish and Wildlife.
U.S. Fish and Wildlife Service (USFWS). 1985. Determination of Carex specuicola to be a threatened species with critical habitat. Federal Register 50(89): 19370-19373.
U.S. Fish and Wildlife Service (USFWS). 2014. Navajo sedge (Carex specuicola) 5-Year Review: Summary and Evaluation. U.S. Fish and Wildlife Service, Arizona Ecological Services Field Office,Phoenix, Arizona.
U.S. Fish and Wildlife Service (USFWS). 2019. Recovery Plan Amendments For Eleven Southwest Species. U.S. Fish and Wildlife Service, Southwest Region, Albuquerque, New Mexico.
Utah TES Plant Interagency Committee. 1991. Endangered, threatened, and sensitive plant field guide. No pagination.

Carex specuicola

Habitat

Reproduction

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