Taxon Report

Juncus leiospermus F.J. Herm. var. ahartii B. Ertter

Ahart's dwarf rush

Print Report

Taxon Summary

Juncus leiospermus var. ahartii, commonly known as Ahart's dwarf rush, is a annual herb in the Juncaceae that is found only in California. It occurs within Valley and foothill grassland, growing at elevations from 30 to 229 meters. Juncus leiospermus var. ahartii is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Juncus leiospermus F.J. Herm. var. ahartii B. Ertter
Common Name:	Ahart's dwarf rush
Family:	Juncaceae
Element Code:	PMJUN011L1
USDA Plants Symbol:	JULEA
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Mar-May	Mar-May
Elevation:	30-229 (100-750)
General Habitats:	Valley and foothill grassland
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G2T1
State Rank:	S1
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	13
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	6
Fair (C)	2
Poor (D)	1
None (X)	1
Unknown (U)	2

Location


California Endemic: True
California Counties and Islands: Name (Code)
Butte (BUT), Calaveras (CAL), Placer (PLA), Sacramento (SAC), Tehama (TEH), Yuba (YUB)
Quads: Name (Quad Code)
Biggs (3912146), Buffalo Creek (3812152)*, Carmichael (3812153), Honcut (3912135), Lincoln (3812183), Loma Rica (3912134), Palermo (3912145), Red Bluff East (4012222), Valley Springs SW (3812018)

Threat List Data from the CNDDB


Threat List Total:	7
EOs with Threat Listed:	Total EOs	% of EOs
	8	62 %
Development	5	38%
Grazing	2	15%
Other	2	15%
Road/trail construction/maint.	1	7%
Agriculture	1	7%
Mining	1	7%
ORV activity	1	7%

Notes



Known from approximately 10 occurrences. Threatened by development. See Memoirs of the New York Botanical Garden 39:49 (1986) 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 19 November 2025].