Taxon Report

Plagiobothrys chorisianus (Chamb.) Jtn. var. chorisianus

Choris' popcornflower

Print Report


Taxon Summary

Plagiobothrys chorisianus var. chorisianus, commonly known as Choris' popcornflower, is a annual herb in the Boraginaceae that is found only in California. It occurs within Chaparral, Coastal prairie, and Coastal scrub, growing at elevations from 3 to 160 meters. Plagiobothrys chorisianus var. chorisianus is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

  Classification
Scientific Name:
 Plagiobothrys chorisianus (Chamb.) Jtn. var. chorisianus
Common Name:
 Choris' popcornflower
Family: Boraginaceae
Element Code: PDBOR0V061
USDA Plants Symbol: PLCHC
Synonyms/Other Names:

Ecology and Life History
Lifeform: annual herb
Blooming Period: Mar-Jun Mar-Jun
Elevation: 3-160 (10-525)
General Habitats: Chaparral, Coastal prairie, Coastal scrub
Microhabitat: Mesic
Microhabitat Details:

Conservation Status
CA Rare Plant Rank: 1B.2
Global Rank: G3T1Q
State Rank:
 S1
State List: None
Fed List: None
Other Status: BLM_S; SB_UCSC
CRPR Changes:

Occurrence Data from the CNDDB
Total Occurrences: 42
Element Occurrence Ranks:
   Excellent (A) 2
   Good (B) 9
   Fair (C) 4
   Poor (D) 0
   None (X) 1
   Unknown (U) 26

Location
California Endemic:  True
California Counties and Islands: Name (Code)
Alameda (ALA)(?), Monterey (MNT), San Francisco (SFO), San Mateo (SMT), Santa Clara (SCL), Santa Cruz (SCR)
Quads: Name (Quad Code)
Ano Nuevo (3712213), Big Basin (3712222), Davenport (3712212), Felton (3712211), Franklin Point (3712223), Half Moon Bay (3712244), La Honda (3712233), Laurel (3712118), Mindego Hill (3712232), Montara Mountain (3712254), Moss Landing (3612177), Oakland West (3712273)*, Palo Alto (3712242), Pigeon Point (3712224), Salinas (3612166), San Francisco North (3712274)(?), San Francisco South (3712264), San Gregorio (3712234), San Mateo (3712253), Watsonville West (3612187), Woodside (3712243)

Threat List Data from the CNDDB

Threat List Total: 10
EOs with Threat Listed: Total EOs % of EOs
17 40 %
Non-native plant impacts 12 28%
Other 8 19%
Foot traffic/trampling 2 4%
Grazing 1 2%
Recreational use (non-ORV) 1 2%
Road/trail construction/maint. 1 2%
Altered flood/tidal/hydrologic regime 1 2%
Development 1 2%
Disking 1 2%
Erosion/runoff 1 2%

Notes
Taxonomic work needed; intergrades with var. hickmanii, and differences may be environmentally induced. Threatened by development, foot traffic, and non-native plants.
Threats:
Taxonomy:

Selected References

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].