Taxon Report

Amaranthus watsonii Standl.

Watson's amaranth

Print Report

Taxon Summary

Amaranthus watsonii, commonly known as Watson's amaranth, is a annual herb in the Amaranthaceae that is found in California and elsewhere. It occurs within Mojavean desert scrub, and Sonoran desert scrub, growing at elevations from 20 to 1700 meters. Amaranthus watsonii is ranked 4.3, Plants of Limited Distribution, A Watch List; Not very threatened in California.

Classification


Scientific Name:	Amaranthus watsonii Standl.
Common Name:	Watson's amaranth
Family:	Amaranthaceae
Element Code:	PDAMA04170
USDA Plants Symbol:	AMWA
Synonyms/Other Names:

Ecology and Life History


Lifeform:	annual herb
Blooming Period: Apr-Sep	Apr-Sep
Elevation:	20-1700 (65-5580)
General Habitats:	Mojavean desert scrub, Sonoran desert scrub
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	4.3
Global Rank:	G5?
State Rank:	S3
State List:	None
Fed List:	None
Other Status:	SB_CalBG/RSABG
CRPR Changes:

Occurrence Data from the CNDDB


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

Location


California Endemic: False
California Counties and Islands: Name (Code)
Imperial (IMP), Los Angeles (LAX), Riverside (RIV), San Bernardino (SBD), Tulare (TUL)
Quads: Name (Quad Code)
Calexico (3211564), Castle Peaks (3511532), Crescent Peak (3511542), Heber (3211565), Hopkins Well (3311458), Mt. Baldy (3411726), Traver (3611944)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	0 %

Notes




Threats:
Potentially threatened by solar energy development and vehicles.
Taxonomy:

Selected References

Bulletin of the Torrey Botanical Club 41:505 (1914)

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].