Lomatium klickitatense

J.A. Alexander & W. Whaley

Klickitat Lomatium

G3Vulnerable Found in 1 roadless area NatureServe Explorer →
G3VulnerableGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.1080451
Element CodePDAPI1B2W0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderApiales
FamilyApiaceae
GenusLomatium
Concept Reference
Alexander, J.A., W. Whaley, and N. Blain. 2018. The Lomatium grayi complex (Apiaceae) of the western United States: a taxonomic revision based on morphometric, essential oil composition, and larva-host coevolution studies. J. Bot. Res. Inst. Texas 12(2): 387-444
Taxonomic Comments
In Alexander et al.'s (2018) revision of the Lomatium grayi complex, they split L. papilioniferum and L. klickitatense from L. grayi var. grayi and elevate L. grayi var. depauperatum (= L. depauperatum) to species level. L. klickitatense is proposed for populations of robust plants from western Klickitat County, Washington, and northern Hood River County, Oregon.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-02-14
Change Date2025-02-14
Edition Date2025-02-14
Edition AuthorsN. Ventrella (2025)
Threat ImpactUnknown
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Lomatium klickitatense is a perennial forb occurring in oak and conifer woodlands, and on talus slopes, outcrops, and hillsides of Klickitat County, Washington, and Hood River and Wasco counties of Oregon in the western United States. This is a recently-described taxon, which was split from the greater L. grayii complex in 2018, and short- and long-term trends are unknown. There are an estimated 47 occurrences rangewide, most of which are restricted to a small range centered around the Klickitat River. Threats include residential and agricultural development, off-road vehicle use, road maintenance and construction, and potentially, renewable resource development. Little is known about the severity and scope of threats, though many populations of Lomatium klickitatense occur on protected lands.
Range Extent Comments
Lomatium klickitatense occurs in the western United States in Klickitat County, Washington and Hood River and Wasco counties of Oregon (Alexander et al. 2018). Its range is limited to the Eastern Cascades Slopes and Foothills ecoregion located to the north and south of the Columbian River Gorge area. Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (RARECAT 2024, iNaturalist 2025, NatureServe 2025, SEINet 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 47 occurrences rangewide (RARECAT 2024, iNaturalist 2025, NatureServe 2025, SEINet 2025).
Threat Impact Comments
Threats to Lomatium klickitatense include conversion of habitat due to agricultural and residential development, and off-road recreational activities (WNHP 2025). Most occurrences are on protected lands where development is minimal (Darrach, pers. comm., 2025). Though grazing occurs in occupied habitat, this species is unpalatable and known to be an "increaser" under grazing pressure. Several populations occur on road-cuts and steep rocky road banks and may be threatened by road maintenance or construction activities (NatureServe 2025). Renewable energy development such as wind and solar is a potential concern, though likely a low level threat (Darrach, pers. comm., 2025).
Ecology & Habitat

Habitat

Lomatium klickitatense occurs in oak/conifer foothills and on the Yakima Plateau and slopes from 100-800 m in elevation (Alexander et al. 2018, FNA 2024). In Oregon, it is found on slopes and hillsides along the Columbia River, and in Washington, on slopes in the Klickitat River Drainage (OSU 2025). Washington populations are typically found on roadcuts, slopes, and meadows with Eriogonum compositum, Trifolium macrocephalum, Achnatherum lemmonii, Quercus garryana, and Pinus ponderosa (WNHP 2025).

Ecology

Lomatium klickitatense is a host plant for larvae of the butterfly Papilio indra subsp. indra (Alexander et al. 2018).

Reproduction

Lomatium klickitatense produces flowers in from April-May, and fruits from May-June (FNA 2024).
Terrestrial Habitats
Forest - MixedWoodland - MixedGrassland/herbaceousBare rock/talus/scree
Other Nations (1)
United StatesN3
ProvinceRankNative
WashingtonS2Yes
OregonS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownUnknown
1.1 - Housing & urban areasUnknownUnknownUnknown
2 - Agriculture & aquacultureUnknownUnknownUnknown
2.1 - Annual & perennial non-timber cropsUnknownUnknownUnknown
3 - Energy production & miningUnknownUnknownUnknown
3.3 - Renewable energyUnknownUnknownUnknown
4 - Transportation & service corridorsLarge - restrictedNegligible or <1% pop. declineHigh (continuing)
4.1 - Roads & railroadsLarge - restrictedNegligible or <1% pop. declineHigh (continuing)

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (1)
Oregon (1)
AreaForestAcres
EagleMt. Hood National Forest16,841
References (9)
  1. Alexander, J.A., W. Whaley, and N. Blain. 2018. The Lomatium grayi complex (Apiaceae) of the western United States: a taxonomic revision based on morphometric, essential oil composition, and larva-host coevolution studies. J. Bot. Res. Inst. Texas 12(2): 387-444
  2. Darrach, Mark E. Personal communication. Research Associate. Herbarium, Burke Museum of Natural History and Culture, University of Washington. Seattle, WA.
  3. Flora of North America Editorial Committee (FNA). 2024. Flora of North America north of Mexico. Vol. 13. Magnoliophyta: Geraniaceae to Apiaceae. Oxford Univ. Press, New York. xxiv + 566 pp.
  4. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  5. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  6. NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2024. Version: 1.1.1 (released Oct 01, 2024).
  7. Oregon State University (OSU). 2025. Oregon Flora website. Oregon State University Herbarium at Oregon State University. Online. Available: https://oregonflora.org/ (accessed 2025).
  8. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  9. Washington Natural Heritage Program (WNHP). 2025. Online Field Guide to the Rare Plants of Washington. Online. Available: https://fieldguide.mt.gov/wa (accessed 2025).