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Clarkia exilis

Lewis & Vasek

Kern River Clarkia

G3Vulnerable Found in 2 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.149916
Element CodePDONA050G0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderMyrtales
FamilyOnagraceae
GenusClarkia
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 - Excel v3.2x
Review Date2024-09-11
Change Date2024-09-11
Edition Date2017-11-09
Edition AuthorsMorse, L.E. (1999), rev. R. Bittman (2014, 2017)
Threat ImpactLow
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Clarkia exilis is an annual forb occurring in cismontane woodlands of the southern Sierra Nevada foothills and Tehachapi Mountain area of Kern and Tulare counties in California. There are between 21 to 80 estimated occurrences of this species, although unconfirmed records from Fresno, San Luis Obispo, and Ventura counties need to be reviewed. Threats to Clarkia exilis are considered to be low.
Range Extent Comments
Clarkia exilis is known from the southern Sierra Nevada foothills and Tehachapi Mountain area in Kern and Tulare counties of California in the western United States (FNA 2021). There are also unconfirmed reports of this species in Fresno, San Luis Obispo, and Ventura counties. Using confirmed records, range extent was estimated to be 3,825 square kilometers.
Occurrences Comments
The number of occurrences was estimated to be between 21 and 80.
Threat Impact Comments
Clarkia exilis is ranked as "not very threatened in California" (CNPS 2024). This ranking means that less than 20% of occurrences are considered threatened, or that there is a low degree and immediacy of threats, or that current threats to the species are unknown
Ecology & Habitat

Habitat

Clarkia exilis occurs in cismontane woodlands (CNPS 2024). Based a study of populations of C. exilis in oak woodlands in Kern county, this species tends to occupy areas with higher soil moisture, such as along the edges of boulder fields and in streambeds (Delesalle and Mazer 2009).
Terrestrial Habitats
Forest/Woodland
Other Nations (1)
United StatesN3
ProvinceRankNative
CaliforniaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (2)
California (2)
AreaForestAcres
Greenhorn CreekSequoia National Forest28,226
Mill CreekSequoia National Forest27,643
References (8)
  1. California Native Plant Society (CNPS), Rare Plant Program. 2024. Inventory of Rare and Endangered Plants of California, online edition, v9.5. Online. Available: https://www.rareplants.cnps.org (accessed 2024).
  2. California Natural Diversity Database (CNDDB). 2014. RareFind Version 5. California Department of Fish and Game, Sacramento.
  3. Delesalle, V. and S. Mazer. 2009. Size-dependent pollen: ovule ratios and the allometry of floral sex allocation in <i>Clarkia</i> (Onagraceae) taxa with contrasting mating systems. American Journal of Botany 96(5): 968-978.
  4. Flora of North America Editorial Committee (FNA). 2021. Flora of North America north of Mexico. Vol. 10. Magnoliophyta: Proteaceae to Elaeagnaceae. Oxford Univ. Press, New York. xxiv + 456 pp.
  5. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  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. Lewis, Harlan, and Margaret Ensign Lewis. 1955. The genus Clarkia. University of California Publications in Botany 20(4): 241-392.
  8. Munz, P.A., with D.D. Keck. 1959. A California flora. Univ. California Press, Berkeley. 1681 pp.