Taxon Report

Chlorogalum grandiflorum Hoover

Red Hills soaproot

Print Report


© 2004 George W. Hartwell

Taxon Summary

Chlorogalum grandiflorum, commonly known as Red Hills soaproot, is a perennial bulbiferous herb in the Agavaceae that is found only in California. It occurs within Chaparral, Cismontane woodland, and Lower montane coniferous forest, growing at elevations from 245 to 1690 meters. Chlorogalum grandiflorum is ranked 4.2, Plants of Limited Distribution, A Watch List; Moderately threatened in California.

  Classification
Scientific Name:
 Chlorogalum grandiflorum Hoover
Common Name:
 Red Hills soaproot
Family: Agavaceae
Element Code: PMLIL0G020
USDA Plants Symbol: CHGR3
Synonyms/Other Names:

Ecology and Life History
Lifeform: perennial bulbiferous herb
Blooming Period: (Apr)May-Jun (Apr)May-Jun
Elevation: 245-1690 (805-5545)
General Habitats: Chaparral, Cismontane woodland, Lower montane coniferous forest
Microhabitat: Gabbroic, Serpentine, Shale
Microhabitat Details:

Conservation Status
CA Rare Plant Rank: 4.2
Global Rank: G3
State Rank:
 S3
State List: None
Fed List: None
Other Status:
CRPR Changes:
  • changed from 1B.2 to 4.2 on 2025-06-24

Occurrence Data from the CNDDB
Total Occurrences: 137
Element Occurrence Ranks:
   Excellent (A) 7
   Good (B) 41
   Fair (C) 19
   Poor (D) 5
   None (X) 0
   Unknown (U) 65

Location
California Endemic:  True
California Counties and Islands: Name (Code)
Amador (AMA), Calaveras (CAL), El Dorado (ELD), Placer (PLA), Tuolumne (TUO)
Quads: Name (Quad Code)
Angels Camp (3812015), Aukum (3812056), Chinese Camp (3712074), Clarksville (3812161), Colfax (3912018), Coloma (3812078), Devil Peak (3812085), Devils Nose (3812044), Dorrington (3812033), Foresthill (3912017), Fort Mountain (3812034), Garden Valley (3812077), Garnet Hill (3812043), Georgetown (3812087), Greek Store (3912015), Greenwood (3812088), Michigan Bluff (3912016), New Melones Dam (3712085), Omo Ranch (3812055), Pilot Hill (3812171), Pine Grove (3812046), Pollock Pines (3812075), Rail Road Flat (3812035), Riverton (3812074), Robbs Peak (3812084), Salt Spring Valley (3812016), Shingle Springs (3812068), Slate Mtn. (3812076), Sonora (3712084), Tunnel Hill (3812086), West Point (3812045)

Threat List Data from the CNDDB

Threat List Total: 15
EOs with Threat Listed: Total EOs % of EOs
68 50 %
Logging 31 22%
Road/trail construction/maint. 25 18%
Other 17 12%
Development 11 8%
Non-native plant impacts 10 7%
ORV activity 4 2%
Mining 4 2%
Biocides 4 2%
Grazing 4 2%
Vandalism/dumping/litter 3 2%
Wood cutting or brush clearing 3 2%
Erosion/runoff 2 1%
Foot traffic/trampling 2 1%
Disking 1 0%
Recreational use (non-ORV) 1 0%

Notes
May benefit from light disturbance and reduced tree canopy.
Threats:
Threatened by development, mining, road construction, and vehicles. Possibly threatened by trail maintenance, herbicide use, logging and non-native plants.
Taxonomy:

Selected References

CRPR List Change on 2025-06-24
Leaflets of Western Botany 2(8):128 (1938)
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 27 June 2025].