CNPS

CNPS Rare Plant Inventory



Taxon Details

Chorizanthe xanti var. leucotheca

white-bracted spineflower

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Taxon Summary:

Chorizanthe xanti var. leucotheca, commonly known as white-bracted spineflower, is a annual herb in the Polygonaceae that is found only in California. It occurs within Coastal scrub (alluvial fans), Mojavean desert scrub, and Pinyon and juniper woodland, growing at elevations from 300 to 1200 meters. Chorizanthe xanti var. leucotheca is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

  Classification

Scientific Name:
Chorizanthe xanti Wats. var. leucotheca Goodm.
Common Name:
white-bracted spineflower
Family: Polygonaceae
Element Code: PDPGN040Z1
USDA Plants Symbol: CHXAL
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: G4T3
State Rank:
 S3
Other Status: BLM_S; SB_CalBG/RSABG; SB_USDA; USFS_S
CRPR Changes:
Add Date: 1994-01-01
Date Edited: 2021-11-05

  Ecology and Life History

Lifeform: annual herb
Blooming Period: Apr-Jun
JFMAMJJASOND
Elevation:
300 - 1200 meters
985 - 3935 feet
General Habitats:
  • Coastal scrub (alluvial fans)
  • Mojavean desert scrub
  • Pinyon and juniper woodland
Microhabitat Details:
Microhabitat:
  • Gravelly (sometimes)
  • Sandy (sometimes)

  Notes

Notes:
Threatened by development, flood control projects, mining, and vehicles. See Annals of the Missouri Botanical Garden 21:60 (1934) for original description, and Phytologia 66(2):160-163 (1989) for taxonomic treatment.
Threats:
Taxonomy:

  Threat List Data from the CNDDB

Threat List Total: 5
Total EOs % of EOs
EOs with Threat Listed: 11 19 %
THREAT LIST:
Development 10 16%
Non-native plant impacts 10 16%
Grazing 8 13%
ORV activity 1 1%
Road/trail construction/maint. 1 1%

  Occurrence Data from the CNDDB

Total Occurrences: 59
Element Occurrence Ranks:
A B C D X U
10 3 0 0 0 46
Occurrence Status:
Historical >20 Years 20
Recent <=20 Years 39
Presence:
Presumed Extant 59
Possibly Extirpated 0
Presumed Extirpated 0

  Location

California Endemic:
California Island:
States: Name (Code)
California (CA)
California Counties and Islands: Name (Code)
Riverside (RIV), San Bernardino (SBD), San Diego (SDG)
Quads: Name (Quad Code)
Anza (3311656), Blackburn Canyon (3311667), Bucksnort Mtn. (3311645), Cabazon (3311687), Cahuilla Mtn. (3311657), Cajon (3411734)?, Catclaw Flat (3411616), Desert Hot Springs (3311685), Devore (3411724), Idyllwild (3311666), Lake Arrowhead (3411732), Morongo Valley (3411615), Old Woman Springs (3411646), Onyx Peak (3411626), Palm Springs (3311675), Palm View Peak (3311665), Telegraph Peak (3411735), Toro Peak (3311654), White Water (3311686), Yucaipa (3411711)
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

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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 16 September 2025].
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