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Chaenactis thompsonii

Cronq.

Thompson's Pincushion

G3Vulnerable Found in 4 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
Medium - lowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.130474
Element CodePDAST200J0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusChaenactis
Other Common Names
Thompson's pincushion (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 Date2025-01-09
Change Date2012-11-01
Edition Date2025-01-09
Edition AuthorsGamon, J. & K. Maybury, rev. A. Treher (2012), rev. Johnson, J. (2025)
Threat ImpactMedium - low
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Chaenactis thompsonii is a perennial herb endemic to a relatively small geographic area in Washington State and mostly restricted to serpentine and peridotite substrates. It is potentially threatened by logging activity, trampling by hikers at one site, road construction, mining, and ski area development.
Range Extent Comments
Chaenactis thompsonii is primarily found in the Wenatchee Mountains of Chelan and Kittitas Counties, Washington, United States. Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, CPNWH 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are 29 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, CPNWH 2025).
Threat Impact Comments
Chaenactis thompsonii is potentially threatened by road construction, mining, and ski area development. Two sites may be threatened by logging activity and trampling by hikers at one site may threaten trailside plants (NatureServe 2025).
Ecology & Habitat

Habitat

Chaenactis thompsonii grows on barren or grassy slopes on serpentine soils (NatureServe 2025).
Terrestrial Habitats
Grassland/herbaceousBarrens
Other Nations (1)
United StatesN3
ProvinceRankNative
WashingtonS3Yes
Threat Assessments
ThreatScopeSeverityTiming
4 - Transportation & service corridorsSmall (1-10%)Serious or 31-70% pop. declineModerate (short-term)
4.1 - Roads & railroadsSmall (1-10%)Serious or 31-70% pop. declineModerate (short-term)
5 - Biological resource useRestricted (11-30%)Serious - slightHigh (continuing)
5.3 - Logging & wood harvestingRestricted (11-30%)Serious - slightHigh (continuing)
6 - Human intrusions & disturbanceSmall (1-10%)Serious - slightHigh (continuing)
6.1 - Recreational activitiesSmall (1-10%)Serious - slightHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (4)
Washington (4)
AreaForestAcres
Alpine Lakes Adj.Wenatchee National Forest57,104
Devils GulchWenatchee National Forest24,419
NaneumWenatchee National Forest4,508
TeanawayWenatchee National Forest72,849
References (9)
  1. Consortium of Pacific Northwest Herbaria (CPNWH). 2025. Online database of vascular plant specimens from the Pacific Northwest. Online. Available: http://www.pnwherbaria.org/index.php (accessed 2025).
  2. Cronquist, A. 1955. Compositae. In C.L. Hitchcock, A. Cronquist, M. Ownbey, and J.W. Thompson (eds.). Vascular plants of the Pacific Northwest. Part 5. Univ. Washington Press, Seattle. 343 pp.
  3. Flora of North America Editorial Committee (FNA). 2006c. Flora of North America north of Mexico. Vol. 21. Magnoliophyta: Asteridae, part 8: Asteraceae, part 3. Oxford Univ. Press, New York. xxii + 616 pp.
  4. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  5. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  6. 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.
  7. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  8. Washington Natural Heritage Program. 1981. An illustrated guide to the endangered, threatened and sensitive vascular plants of Washington. Washington Natural Heritage Program, Olympia. 328 pp.
  9. Washington Natural Heritage Program. 1994. Endangered, threatened and sensitive vascular plants of Washington. Dept. of Natural Resources, Olympia, Washington. 52 pp.