CNPS

CNPS Rare Plant Inventory



Taxon Details

Hesperolinon adenophyllum

glandular western flax

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Photo of Hesperolinon adenophyllum
© 2002 John Game 		Photo of Hesperolinon adenophyllum
© 2017 John Doyen 		Photo of Hesperolinon adenophyllum
© 2002 John Game

Taxon Summary:

Hesperolinon adenophyllum, commonly known as glandular western flax, is a annual herb in the Linaceae that is found only in California. It occurs within Chaparral, Cismontane woodland, and Valley and foothill grassland, growing at elevations from 150 to 1315 meters. Hesperolinon adenophyllum is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

  Classification

Scientific Name:
Hesperolinon adenophyllum (Gray) Small
Common Name:
glandular western flax
Family: Linaceae
Element Code: PDLIN01010
USDA Plants Symbol: HEAD
Synonyms/Other Names:
Name Status: JEF, FNA, POWO,
IPNI, Tropicos

  Conservation Status

CA Rare Plant Rank: 1B.2
Fed List: None
State List: None
Global Rank: G2G3
State Rank:
 S2S3
Other Status: BLM_S
CRPR Changes:
Add Date: 1974-01-01
Date Edited: 2022-03-01

  Ecology and Life History

Lifeform: annual herb
Blooming Period: May-Aug
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Elevation:
150 - 1315 meters
490 - 4315 feet
General Habitats:
  • Chaparral
  • Cismontane woodland
  • Valley and foothill grassland
Microhabitat Details:
Microhabitat:
  • Serpentine (usually)

  Notes

Notes:
Threats:

Threatened by geothermal development, recreation, and grazing. Potentially threatened by urban development.
Taxonomy:

  Threat List Data from the CNDDB

Threat List Total: 9
Total EOs % of EOs
EOs with Threat Listed: 14 29 %
THREAT LIST:
Road/trail construction/maint. 7 14%
Other 4 8%
Development 4 8%
Biocides 3 6%
Erosion/runoff 2 4%

  Occurrence Data from the CNDDB

Total Occurrences: 48
Element Occurrence Ranks:
A B C D X U
2 10 1 0 0 35
Occurrence Status:
Historical >20 Years 39
Recent <=20 Years 9
Presence:
Presumed Extant 48
Possibly Extirpated 0
Presumed Extirpated 0

  Location

California Endemic:
California Island:
States: Name (Code)
California (CA)
California Counties and Islands: Name (Code)
Lake (LAK), Mendocino (MEN)
Quads: Name (Quad Code)
Bartlett Mtn. (3912227), Burbeck (3912344), Cow Mountain (3912321), Crockett Peak (3912247), Elk Mountain (3912238), Foster Mtn. (3912342), Greenough Ridge (3912334), Highland Springs (3812288), Kelseyville (3812287), Lake Pillsbury (3912248), Lakeport (3912218), Laughlin Range (3912333), Laytonville (3912364), Longvale (3912354), Lucerne (3912217), Potato Hill (3912237), Potter Valley (3912331), Sanhedrin Mtn. (3912351), The Geysers (3812277), Upper Lake (3912228), Van Arsdale Reservoir (3912341), Whispering Pines (3812276), Willits (3912343)
Notes:
Definitions of codes following a county and/or quad:
* Presumed extirpated
(?) Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.
Regional Map

  Map

Presumed Extant
Click on quad for name. Hold Shift Key to use mouse scroll wheel

  Selected References

Original Description: Proceedings of the American Academy of Arts and Sciences 8:624-625 (1873)
Taxonomic Treatment: University of California Publications in Botany 32:235-314 (1961)
Species Account: Hesperolinon adenophyllum profile for potential Species of Conservation Concern evaluation (2018)
Other: USFS Potential Species of Conservation Concern Profile

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Suggested Citation:
California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 26 January 2025].
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