Taxon Report

Juncus cooperi Engelm.

Cooper's rush

Print Report


© 2018 Neal Kramer

Taxon Summary

Juncus cooperi, commonly known as Cooper's rush, is a perennial herb in the Juncaceae that is found in California and elsewhere. It occurs within Meadows and seeps (mesic, and alkaline or saline), growing at elevations from -260 to 1770 meters. Juncus cooperi is ranked 4.3, Plants of Limited Distribution, A Watch List; Not very threatened in California.

  Classification
Scientific Name:
 Juncus cooperi Engelm.
Common Name:
 Cooper's rush
Family: Juncaceae
Element Code: PMJUN010T0
USDA Plants Symbol: JUCO3
Synonyms/Other Names:

Ecology and Life History
Lifeform: perennial herb
Blooming Period: Apr-May(Aug) Apr-May(Aug)
Elevation: -260-1770 (-855-5805)
General Habitats: Meadows and seeps
Microhabitat:
Microhabitat Details:

Conservation Status
CA Rare Plant Rank: 4.3
Global Rank: G4
State Rank:
 S3
State List: None
Fed List: None
Other Status: SB_CalBG/RSABG
CRPR Changes:

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

Location
California Endemic:  False
California Counties and Islands: Name (Code)
Imperial (IMP), Inyo (INY), Riverside (RIV), San Bernardino (SBD), San Diego (SDG)
Quads: Name (Quad Code)
Badwater (3611627), Ballarat (3611712), Beatty Junction (3611658), Carrizo Mtn. NE (3211681), Chloride City (3611668), Cottonwood Canyon (3611753), Craig Canyon (3611767), Devils Golf Course (3611637), Devils Speedway (3611638), Durmid (3311547), East of Echo Canyon (3611645), Echo Canyon (3611646), Frink (3311536), Furnace Creek (3611647), Grapevine Peak (3611782), Jacumba (3211662), Jail Canyon (3611722), Lower Warm Springs (3611777), Manix (3411685), Myoma (3311673), Nevares Peak (3611657), Oasis (3311641), Old Ibex Pass (3511664), Orocopia Canyon (3311557), Palm View Peak (3311665), Panamint Butte (3611743), Paradise Range (3511627), Resting Spring (3511682), Seventeen Palms (3311631), Shoshone (3511683), Soda Lake North (3511621), Tecopa (3511672), Thimble Peak (3611771), Topock (3411464), Twelvemile Spring (3611612), Ubehebe Crater (3711714), West of Furnace Creek (3611648), West of Teakettle Junction (3611776), Wister (3311535)

Threat List Data from the CNDDB

Threat List Total: 0
EOs with Threat Listed: Total EOs % of EOs
0 0 %

Notes
Possibly threatened by hydrologic alterations and grazing. See Transactions of the Academy of Science of St. Louis 2:590 (1868) for original description.
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 6 March 2025].