Taxon Report

Erigeron maniopotamicus G.L. Nesom & T.W. Nelson

Mad River fleabane daisy

Print Report

Taxon Summary

Erigeron maniopotamicus, commonly known as Mad River fleabane daisy, is a perennial herb in the Asteraceae that is found only in California. It occurs within Lower montane coniferous forest, Meadows and seeps (openings, and dry), growing at elevations from 1275 to 1500 meters. Erigeron maniopotamicus is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Erigeron maniopotamicus G.L. Nesom & T.W. Nelson
Common Name:	Mad River fleabane daisy
Family:	Asteraceae
Element Code:	PDASTE1050
USDA Plants Symbol:	ERMA19
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: May-Aug	May-Aug
Elevation:	1275-1500 (4185-4920)
General Habitats:	Lower montane coniferous forest, Meadows and seeps
Microhabitat:	Disturbed areas, Openings, Roadsides, Rocky
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G1G2
State Rank:	S1S2
State List:	None
Fed List:	None
Other Status:	BLM_S; SB_UCSC; USFS_S
CRPR Changes:	added to 1B on 2005-02-10

Occurrence Data from the CNDDB


Total Occurrences:	10
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	3
Fair (C)	1
Poor (D)	0
None (X)	0
Unknown (U)	6

Location


California Endemic: True
California Counties and Islands: Name (Code)
Humboldt (HUM), Trinity (TRI)
Quads: Name (Quad Code)
Board Camp Mtn. (4012366), Dinsmore (4012345), Lake Mountain (4012314), Zenia (4012324)

Threat List Data from the CNDDB


Threat List Total:	5
EOs with Threat Listed:	Total EOs	% of EOs
	9	90 %
Road/trail construction/maint.	6	60%
Logging	5	50%
Grazing	2	20%
ORV activity	1	10%
Other	1	10%

Notes



Known from widely disjunct locations in east-central HUM Co. and adjacent TRI Co. Potentially threatened by road maintenance, road construction, grazing, and logging. Not in TJM (1993). See SIDA 21(2): 673 (2004) for original description.
Threats:

Taxonomy:

Selected References

CRPR List Addition on 2005-02-10

Erigeron maniopotamicus profile for potential Species of Conservation Concern evaluation (2018)

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 13 November 2025].