Taxon Report

Orcuttia inaequalis Hoov.

San Joaquin Valley Orcutt grass

Print Report


Taxon Summary

Orcuttia inaequalis, commonly known as San Joaquin Valley Orcutt grass, is a annual herb in the Poaceae that is found only in California. It occurs within Vernal pools, growing at elevations from 10 to 755 meters. Orcuttia inaequalis is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

  Classification
Scientific Name:
 Orcuttia inaequalis Hoov.
Common Name:
 San Joaquin Valley Orcutt grass
Family: Poaceae
Element Code: PMPOA4G060
USDA Plants Symbol: ORIN
Synonyms/Other Names:
  • Orcuttia californica (Hoov.) Hoov. var. inaequalis

Ecology and Life History
Lifeform: annual herb
Blooming Period: Apr-Sep Apr-Sep
Elevation: 10-755 (35-2475)
General Habitats: Vernal pools
Microhabitat:
Microhabitat Details:

Conservation Status
CA Rare Plant Rank: 1B.1
Global Rank: G1
State Rank:
 S1
State List: CE
Fed List: FT
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB
Total Occurrences: 47
Element Occurrence Ranks:
   Excellent (A) 5
   Good (B) 9
   Fair (C) 8
   Poor (D) 2
   None (X) 17
   Unknown (U) 6

Location
California Endemic:  True
California Counties and Islands: Name (Code)
Fresno (FRE), Madera (MAD), Merced (MER), Solano (SOL), Stanislaus (STA)*, Tulare (TUL)
Quads: Name (Quad Code)
Cressey (3712046)*, Daulton (3711918), Denair (3712057)*, Elmira (3812138), Fresno North (3611977)*, Friant (3611986), Haystack Mtn. (3712043), Ivanhoe (3611942)*, Kismet (3712011)*, Lanes Bridge (3611987), Le Grand (3712022), Merced (3712034), Millerton Lake East (3711915), Monson (3611943), Montpelier (3712056)*, Orange Cove North (3611963), Owens Reservoir (3712032), Paulsell (3712066)*, Planada (3712033), Wahtoke (3611964)*, Waterford (3712067)*, Woodlake (3611941), Yosemite Lake (3712044)

Threat List Data from the CNDDB

Threat List Total: 14
EOs with Threat Listed: Total EOs % of EOs
37 79 %
Grazing 23 48%
Non-native plant impacts 11 23%
Agriculture 10 21%
Development 9 19%
Altered flood/tidal/hydrologic regime 6 12%
Foot traffic/trampling 6 12%
ORV activity 4 8%
Other 3 6%
Disking 2 4%
Road/trail construction/maint. 2 4%
Vandalism/dumping/litter 1 2%
Erosion/runoff 1 2%
Dam/Inundation 1 2%
Recreational use (non-ORV) 1 2%

Notes
Seriously threatened by agriculture, development, overgrazing, channelization, and non-native plants. See Madroño 3(6):229 (1936) for original description, and American Journal of Botany 69:1082-1095 (1982) for taxonomic treatment.
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 12 February 2025].