Taxon Report

Clarkia speciosa Lewis & Lewis ssp. immaculata Lewis & Lewis

Pismo clarkia

Print Report


Taxon Summary

Clarkia speciosa ssp. immaculata, commonly known as Pismo clarkia, is a annual herb in the Onagraceae that is found only in California. It occurs within Chaparral (margins, openings), Cismontane woodland, and Valley and foothill grassland, growing at elevations from 25 to 185 meters. Clarkia speciosa ssp. immaculata is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.


  Classification

Scientific Name:
Clarkia speciosa Lewis & Lewis ssp. immaculata Lewis & Lewis
Common Name:
Pismo clarkia
Family: Onagraceae
Element Code: PDONA05111
USDA Plants Symbol: CLSPI
Synonyms/Other Names:

Ecology and Life History

Lifeform: annual herb
Blooming Period: May-Jul May-Jul
Elevation: 25-185 (80-605)
General Habitats: Chaparral, Cismontane woodland, Valley and foothill grassland
Microhabitat: Sandy
Microhabitat Details:

Occurrence Data from the CNDDB

Total Occurrences: 26
Element Occurrence Ranks:
   Excellent (A) 2
   Good (B) 8
   Fair (C) 3
   Poor (D) 1
   None (X) 5
   Unknown (U) 7
California Endemic:  True
California Counties and Islands: Name (Code)
San Luis Obispo (SLO)
Quads: Name (Quad Code)
Arroyo Grande NE (3512025), Morro Bay South (3512037), Oceano (3512015), Pismo Beach (3512026)

Threat List Data from the CNDDB

Threat List Total: 12
EOs with Threat Listed: Total EOs % of EOs
21 81 %
Development 17 65%
Road/trail construction/maint. 6 23%
Wood cutting or brush clearing 6 23%
Non-native plant impacts 5 19%
Grazing 4 15%
Foot traffic/trampling 3 11%
Biocides 1 3%
Erosion/runoff 1 3%
Mining 1 3%
ORV activity 1 3%
Other 1 3%
Vandalism/dumping/litter 1 3%

Notes

Threatened by development and road maintenance, and possibly by grazing. USFWS uses the name C. speciosa var. immaculata. See University of California Publications in Botany 20:291 (1955) for original description.
Threats:
Taxonomy:
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 5 February 2025].