Taxon Report

Ageratina shastensis (D.W. Taylor & Steb.) R.M. King & H. Robinson

Shasta ageratina

Print Report

Taxon Summary

Ageratina shastensis, commonly known as Shasta ageratina, is a perennial herb in the Asteraceae that is found only in California. It occurs within Chaparral, and Lower montane coniferous forest, growing at elevations from 400 to 1800 meters. Ageratina shastensis is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Ageratina shastensis (D.W. Taylor & Steb.) R.M. King & H. Robinson
Common Name:	Shasta ageratina
Family:	Asteraceae
Element Code:	PDASTBX0R0
USDA Plants Symbol:	AGSH2
Synonyms/Other Names:	Eupatorium shastense D.W. Taylor & Stebb.

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Jun-Oct	Jun-Oct
Elevation:	400-1800 (1310-5905)
General Habitats:	Chaparral, Lower montane coniferous forest
Microhabitat:	Carbonate (often), Rocky
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G3
State Rank:	S3
State List:	None
Fed List:	None
Other Status:	SB_UCSC
CRPR Changes:	changed from 4.2 to 1B.2 on 2008-10-14

Occurrence Data from the CNDDB


Total Occurrences:	27
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	20
Fair (C)	2
Poor (D)	0
None (X)	0
Unknown (U)	5

Location


California Endemic: True
California Counties and Islands: Name (Code)
Shasta (SHA)
Quads: Name (Quad Code)
Bollibokka Mtn. (4012282), Devils Rock (4012271), Goose Gap (4012281), Hanland Peak (4012283), Lake McCloud (4112221), O'Brien (4012273), Shoeinhorse Mtn. (4112211), Tombstone Mtn. (4112213), Yellowjacket Mtn. (4112212)

Threat List Data from the CNDDB


Threat List Total:	3
EOs with Threat Listed:	Total EOs	% of EOs
	8	30 %
Logging	5	18%
Road/trail construction/maint.	5	18%
Recreational use (non-ORV)	1	3%

Notes



Threatened by mining. See Madroño 25(4):218-220 (1978) for original description.
Threats:

Taxonomy:

Selected References

Proposed Change from California Rare Plant Rank 4.2 to 1B.2 (2008)

Ageratina shastensis account for potential Species of Conservation Concern evaluation (2021)

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 4 November 2025].