Species Details

Ambrosia pumila

San Diego ambrosia

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Classification

Scientific Name: Ambrosia pumila (Nutt.) Gray
Common Name: San Diego ambrosia
Family:	Asteraceae
Element Code:	PDAST0C0M0
USDA Plants Symbol:	AMPU4
Synonyms/Other Names:

Conservation Status

CA Rare Plant Rank:	1B.1
Fed List:	FE (2002-07-02)
State List:	None
Global Rank:	G1
State Rank:	S1
Other Status:	SB_CRES
CRPR Changes:
Add Date:	1974-01-01
Date Edited:	2022-08-02

Ecology and Life History

Lifeform: perennial rhizomatous herb

Blooming Period: Apr-Oct

Elevation:
20 - 415 meters
65 - 1360 feet

General Habitats:

Chaparral
Coastal scrub
Valley and foothill grassland
Vernal pools

Microhabitat Details:

Microhabitat:

Alkaline (sometimes)
Clay (sometimes)
Disturbed areas (often)
Loam (sometimes)
Sandy (sometimes)

Notes

Notes: Threatened by development, non-native plants, vehicles, road maintenance, and foot traffic. Confused with A. confertiflora, but the two are quite distinct. See Madroño 39(2):157 (1992) for first RIV Co. record.
Threats:
Taxonomy:

Threat List Data from the CNDDB

THREAT LIST:
Threat List Total:	17
	Total EOs	% of EOs
EOs with Threat Listed:	54	89 %
Development	43	70%
Non-native plant impacts	29	47%
Foot traffic/trampling	15	24%
Road/trail construction/maint.	15	24%
Other	14	22%
Vandalism/dumping/litter	8	13%
Wood cutting or brush clearing	7	11%
Recreational use (non-ORV)	6	9%
Erosion/runoff	5	8%
ORV activity	4	6%
Disking	4	6%
Agriculture	2	3%
Grazing	2	3%
Mining	1	1%
Altered flood/tidal/hydrologic regime	1	1%
Biocides	1	1%
Over-collecting/poaching	1	1%

Occurrence Data from the CNDDB

Element Occurrence Ranks:
Total Occurrences:					61
A	B	C	D	X	U
2	6	9	7	21	16

Occurrence Status:
Historical >20 Years	22
Recent <=20 Years	39

Presence:
Presumed Extant	40
Possibly Extirpated	6
Presumed Extirpated	15

Location

California Endemic:

California Island:

States: Name (Code)
Baja California (BA), California (CA)

California Counties and Islands: Name (Code)
Riverside (RIV), San Diego (SDG)

Quads: Name (Quad Code)
Aguanga (3311647), Alberhill (3311764), Bachelor Mtn. (3311751), Bonsall (3311732), Del Mar (3211782), El Cajon (3211678), Escondido (3311711), Imperial Beach (3211751), Jamul Mountains (3211668), La Jolla (3211772), La Mesa (3211771), Lake Elsinore (3311763), National City (3211761), Oceanside (3311724), Rancho Santa Fe (3311712), Riverside West (3311784)*, San Luis Rey (3311723), Temecula (3311742), Vail Lake (3311648)

Notes:

Definitions of codes following a county and/or quad:
*		Presumed extirpated
(?)		Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.

Regional Map

Map

Presumed Extant

Click on quad for name. Hold Shift Key to use mouse scroll wheel

CNPS Rare Plant Inventory