Taxon Report

Eriodictyon altissimum Wells

Indian Knob mountainbalm

Print Report

Aaron Schusteff

Taxon Summary

Eriodictyon altissimum, commonly known as Indian Knob mountainbalm, is a perennial evergreen shrub in the Namaceae that is found only in California. It occurs within Chaparral (maritime), Cismontane woodland, and Coastal scrub, growing at elevations from 80 to 270 meters. Eriodictyon altissimum is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Eriodictyon altissimum Wells
Common Name:	Indian Knob mountainbalm
Family:	Namaceae
Element Code:	PDHYD04010
USDA Plants Symbol:	ERAL12
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial evergreen shrub
Blooming Period: Mar-Jun	Mar-Jun
Elevation:	80-270 (260-885)
General Habitats:	Chaparral, Cismontane woodland, Coastal scrub
Microhabitat:	Sandstone
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	CE
Fed List:	FE
Other Status:	SB_CalBG/RSABG; SB_USDA
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	6
Element Occurrence Ranks:
Excellent (A)	1
Good (B)	1
Fair (C)	2
Poor (D)	0
None (X)	1
Unknown (U)	1

Location


California Endemic: True
California Counties and Islands: Name (Code)
San Luis Obispo (SLO)
Quads: Name (Quad Code)
Morro Bay South (3512037), Pismo Beach (3512026)

Threat List Data from the CNDDB


Threat List Total:	8
EOs with Threat Listed:	Total EOs	% of EOs
	5	83 %
Other	2	33%
Recreational use (non-ORV)	2	33%
Road/trail construction/maint.	1	16%
Wood cutting or brush clearing	1	16%
Development	1	16%
Erosion/runoff	1	16%
Foot traffic/trampling	1	16%
Improper burning regime	1	16%

Notes



Known only from the Irish Hills and Indian Knob. Threatened by urbanization, energy development, and vehicles. Possibly threatened by alteration of fire regimes and non-native plants. See Madroño 16(6):184-186 (1962) 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 26 October 2025].