Home/Species/ Henderson's Phlox

Phlox hendersonii

(E. Nels.) Cronq.

Henderson's Phlox

G3Vulnerable Found in 5 roadless areas NatureServe Explorer →

G3VulnerableGlobal Rank

Medium - lowThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.147608

Element CodePDPLM0D0Z0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

Endemicendemic to a single nation

KingdomPlantae

PhylumAnthophyta

ClassDicotyledoneae

OrderSolanales

FamilyPolemoniaceae

GenusPhlox

Other Common Names

Henderson's phlox (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.

Conservation Status

Rank Method Rank calculation - Biotics v2

Review Date2023-08-28

Change Date2023-08-28

Edition Date2023-08-28

Edition AuthorsNordman, C. (2023).

Threat ImpactMedium - low

Range Extent20,000-200,000 square km (about 8000-80,000 square miles)

Number of Occurrences6 - 20

Rank Reasons

Henderson's Phlox (Phlox hendersonii) occurs in the northwestern United States, in high elevation alpine habitats in Washington and northern Oregon, it is estimated that there are fewer than 20 occurrences rangewide, including within some National Forest Wilderness Areas and National Parks. Threats to Phlox hendersonii may include impacts from plant collecting, recreational impacts and the effects of long-term or extreme drought which may be exacerbated by climate change.

Range Extent Comments

Henderson's Phlox (Phlox hendersonii) occurs in the northwestern United States, in high elevation alpine habitats in Washington and northern Oregon. Range extent was estimated to be 26,000 square kilometers, using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1992 and 2023 (CPNWH 2023, GBIF 2023, iNaturalist 2023, NatureServe 2023, SEINet 2023).

Occurrences Comments

By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1992 and 2023, it is estimated that there are fewer than 20 occurrences rangewide (CPNWH 2023, GBIF 2023, iNaturalist 2023, NatureServe 2023, SEINet 2023).

Threat Impact Comments

Threats to Phlox hendersonii may include impacts from plant collecting, recreational impacts and the effects of long-term or extreme drought which may be exacerbated by climate change.

Ecology & Habitat

Habitat

This species is found in open, exposed rocky areas above the timberline at 1982 to 2591 meters (6500 to 8500 feet) elevation, associated species include Carex nardina (CPNWH 2023, Douglas and Bliss 1977, Kemp and Butler 1989).

Terrestrial Habitats

AlpineBare rock/talus/scree

Other Nations (1)

United StatesN3

Province	Rank	Native
Oregon	S1	Yes
Washington	SNR	Yes

Threat Assessments

Threat	Scope	Severity	Timing
5 - Biological resource use	Small (1-10%)	Serious or 31-70% pop. decline	High (continuing)
5.2 - Gathering terrestrial plants	Small (1-10%)	Serious or 31-70% pop. decline	High (continuing)
6 - Human intrusions & disturbance	Restricted (11-30%)	Moderate or 11-30% pop. decline	High (continuing)
6.1 - Recreational activities	Restricted (11-30%)	Moderate or 11-30% pop. decline	High (continuing)
11 - Climate change & severe weather	Large (31-70%)	Moderate - slight	High (continuing)
11.2 - Droughts	Large (31-70%)	Moderate - slight	High (continuing)

Plant Characteristics

DurationPERENNIAL

Economic Value (Genus)No

Roadless Areas (5)

Oregon (1)

Area	Forest	Acres
Wind Creek	Mt. Hood National Forest	5,438

Washington (4)

Area	Forest	Acres
Chelan	Wenatchee National Forest	74,650
Myrtle Lake	Wenatchee National Forest	11,133
Quilcene	Olympic National Forest	18,656
Teanaway	Wenatchee National Forest	72,849

References (8)

Consortium of Pacific Northwest Herbaria (CPNWH). 2023. Specimen Database. Online. Available: http://www.pnwherbaria.org/data/search.php (accessed 2023).
Douglas, G.W., and L.C. Bliss. 1977. Alpine and high subalpine plant communities of the North Cascades Range, Washington and British Columbia. Ecological Monographs 47 (2):113-150.
Global Biodiversity Information Facility (GBIF). 2023. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2023).
iNaturalist. 2023. Online. Available: https://www.inaturalist.org (accessed 2023).
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.
Kemp, L. and T. Butler. 1989. Mt. Hood National Forest Sensitive Plants and Noxious Weeds Field Guide. US Department of Agriculture, Forest Service, Pacific Northwest Region, Mt. Hood National Forest. Online. Available https://books.google.com/books?hl=en&lr=&id=t4zdJwVkVWkC&oi=fnd&pg=PA1&dq=Phlox+hendersonii&ots=OhzPHjFHYf&sig=5cbRbs1AvLJW4_eceOkMFLj0Oek (accessed 2023).
NatureServe. 2023. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
Southwest Environmental Information Network (SEINet). 2023. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2023).

Phlox hendersonii

Habitat

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