Penstemon wilcoxii

Rydb.

Wilcox's Beardtongue

G5Secure Found in 28 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.148375
Element CodePDSCR1L6Q0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderPlantaginales
FamilyPlantaginaceae
GenusPenstemon
Other Common Names
Wilcox's penstemon (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 Date2026-07-29
Change Date2026-07-29
Edition Date2026-07-29
Edition AuthorsSoteropoulos (2026)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Penstemon wilcoxii is a wide-ranging perennial herb found in a variety of habitats, including shrubby areas, forests, and woodlands. It is endemic to the northwestern United States from western Montana to eastern Washington and northeastern Oregon, with a disjunct occurrence in south-central Washington. There are over 300 occurrences, which face threats from habitat loss, rights-of-way maintenance, recreational activities, hybridization with P. albertinus, and over-collecting for nursery plants. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.
Range Extent Comments
Penstemon wilcoxii is endemic to the northwestern United States from western Montana to eastern Washington and northeastern Oregon, with a disjunct occurrence in south-central Washington (FNA 2019, MTNHP 2026, WANHP 2026). Range extent was estimated to be approximately 250,000 square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2026 (RARECAT 2026, GBIF 2026, NatureServe 2026).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2026, it is estimated that there are over 300 occurrences rangewide (RARECAT 2026, GBIF 2026, NatureServe 2026).
Threat Impact Comments
This species faces threats from habitat loss, rights-of-way maintenance, recreational activities, hybridization with P. albertinus, and over-collecting for nursery plants, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species rangewide (FNA 2019, NatureServe 2026, WANHP 2026). However, their overall impact is likely negligible given the species' broad range, large number of occurrences, and affinity for typically abundant habitats.
Ecology & Habitat

Habitat

Penstemon wilcoxii grows in a variety of habitats, on rocky or gravelly slopes in shrubby areas, forests, and woodlands, as well as roadcuts (FNA 2019, WANHP 2026).

Reproduction

This species flowers from May to August (FNA 2019).
Terrestrial Habitats
Forest/WoodlandCropland/hedgerow
Other Nations (1)
United StatesN5
ProvinceRankNative
WashingtonS1Yes
MontanaS4Yes
IdahoSNRYes
OregonSNRYes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownHigh (continuing)
4 - Transportation & service corridorsUnknownUnknownHigh (continuing)
4.1 - Roads & railroadsUnknownUnknownHigh (continuing)
5 - Biological resource useUnknownUnknownHigh (continuing)
5.2 - Gathering terrestrial plantsUnknownUnknownHigh (continuing)
5.2.1 - Intentional use (species being assessed is the target)UnknownUnknownHigh (continuing)
6 - Human intrusions & disturbanceUnknownUnknownHigh (continuing)
6.1 - Recreational activitiesUnknownUnknownHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownHigh (continuing)
8.3 - Introduced genetic materialUnknownUnknownHigh (continuing)

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (28)
Idaho (5)
AreaForestAcres
Bighorn - WeitasNez Perce-Clearwater National Forest254,845
NeedlesPayette National Forest131,279
North Lochsa SlopeNez Perce-Clearwater National Forest117,662
Peace RockBoise National Forest191,734
SeceshPayette National Forest248,088
Montana (17)
AreaForestAcres
Allan Mountain (01946)Bitterroot National Forest104,184
Anderson MountainBeaverhead-Deerlodge National Forest31,501
Bear - Marshall - Scapegoat - SwanLolo National Forest118,485
Bear - Marshall - Scapegoat - SwanLewis and Clark National Forest344,022
Bmss Ra 1485Flathead National Forest334,275
Gilt Edge - Silver CreekLolo National Forest10,055
HoodooLolo National Forest105,162
North SiegelLolo National Forest9,208
Patricks Knob - North CutoffLolo National Forest16,970
Petty MountainLolo National Forest16,178
QuiggLolo National Forest67,267
Reservation DivideLolo National Forest16,908
Scotchman Peaks (MT)Kootenai National Forest53,909
Selway - Bitterroot (01067)Bitterroot National Forest114,953
Silver KingBeaverhead-Deerlodge National Forest64,289
Silver KingLolo National Forest12,816
South Siegel - South CutoffLolo National Forest13,474
Oregon (6)
AreaForestAcres
Boulder ParkWallowa-Whitman National Forest12,141
HomesteadWallowa-Whitman National Forest5,817
Hurricane CreekWallowa-Whitman National Forest1,606
Lake ForkWallowa-Whitman National Forest21,936
Little SheepWallowa-Whitman National Forest5,238
Snake RiverWallowa-Whitman National Forest31,229
References (4)
  1. Flora of North America Editorial Committee (FNA). 2019. Flora of North America north of Mexico. Vol. 17: Magnoliophyta: Tetrachondraceae to Orobanchaceae. Oxford Univ. Press, New York. xxiv + 737 pp.
  2. 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.
  3. Montana Natural Heritage Program (MTNHP). 2026. Montana Field Guide. Online. Available: http://fieldguide.mt.gov (Accessed 2026).
  4. Washington Natural Heritage Program (WNHP). 2026. Online Field Guide to the Rare Plants of Washington. Online. Available: https://fieldguide.mt.gov/wa (accessed 2026).