Taxon Report

Eriogonum butterworthianum J.T. Howell

Butterworth's buckwheat

Print Report

Taxon Summary

Eriogonum butterworthianum, commonly known as Butterworth's buckwheat, is a perennial herb in the Polygonaceae that is found only in California. It occurs within Chaparral (sandstone), and Valley and foothill grassland, growing at elevations from 585 to 740 meters. Eriogonum butterworthianum is ranked 1B.3, Plants Rare, Threatened or Endangered in California and Elsewhere; Not very threatened in California.

Classification


Scientific Name:	Eriogonum butterworthianum J.T. Howell
Common Name:	Butterworth's buckwheat
Family:	Polygonaceae
Element Code:	PDPGN080X0
USDA Plants Symbol:	ERBU2
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Jun-Jul	Jun-Jul
Elevation:	585-740 (1920-2430)
General Habitats:	Chaparral, Valley and foothill grassland
Microhabitat:	Sandstone, Sandy
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.3
Global Rank:	G1
State Rank:	S1
State List:	CR
Fed List:	None
Other Status:	BLM_S; SB_UCSC; USFS_S
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	4
Element Occurrence Ranks:
Excellent (A)	2
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	2

Location


California Endemic: True
California Counties and Islands: Name (Code)
Monterey (MNT)
Quads: Name (Quad Code)
Cone Peak (3612114), Junipero Serra Peak (3612124), Reliz Canyon (3612123)

Threat List Data from the CNDDB


Threat List Total:	2
EOs with Threat Listed:	Total EOs	% of EOs
	1	25 %
Foot traffic/trampling	1	25%
Other	1	25%

Notes



Known from only four occurrences near Arroyo Seco in the Santa Lucia Mtns.
Threats:
Potentially threatened by foot traffic.
Taxonomy:
See Leaflets of Western Botany 9(9-10):153-154 (1961) for original description, and Phytologia 66(4):328 (1989) for taxonomic treatment.

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].