Taxon Report

Arctostaphylos glandulosa Eastw. ssp. crassifolia (Jeps.) Wells

Del Mar manzanita

Print Report


© 2012 Neal Kramer

Taxon Summary

Arctostaphylos glandulosa ssp. crassifolia, commonly known as Del Mar manzanita, is a perennial evergreen shrub in the Ericaceae that is found in California and elsewhere. It occurs within Chaparral (maritime, and sandy), growing at elevations from 0 to 365 meters. Arctostaphylos glandulosa ssp. crassifolia is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.


  Classification

Scientific Name:
Arctostaphylos glandulosa Eastw. ssp. crassifolia (Jeps.) Wells
Common Name:
Del Mar manzanita
Family: Ericaceae
Element Code: PDERI040E8
USDA Plants Symbol: ARGLC4
Synonyms/Other Names:

Ecology and Life History

Lifeform: perennial evergreen shrub
Blooming Period: Jun-Apr Jun-Apr
Elevation: 0-365 (0-1200)
General Habitats: Chaparral
Microhabitat:
Microhabitat Details:

Occurrence Data from the CNDDB

Total Occurrences: 57
Element Occurrence Ranks:
   Excellent (A) 2
   Good (B) 13
   Fair (C) 3
   Poor (D) 4
   None (X) 2
   Unknown (U) 33
California Endemic:  False
California Counties and Islands: Name (Code)
San Diego (SDG)
Quads: Name (Quad Code)
Del Mar (3211782), Encinitas (3311713), La Mesa (3211771), Poway (3211781), Rancho Santa Fe (3311712), San Luis Rey (3311723), San Marcos (3311722)

Threat List Data from the CNDDB

Threat List Total: 16
EOs with Threat Listed: Total EOs % of EOs
38 67 %
Development 28 49%
Improper burning regime 22 38%
Non-native plant impacts 9 15%
Road/trail construction/maint. 7 12%
Recreational use (non-ORV) 6 10%
Other 5 8%
Insufficient population/stand size 5 8%
Hybridization 5 8%
Foot traffic/trampling 5 8%
Vandalism/dumping/litter 4 7%
Wood cutting or brush clearing 1 1%
ORV activity 1 1%
Grazing 1 1%
Erosion/runoff 1 1%
Agriculture 1 1%
Military operations 1 1%

Notes

Threatened by urbanization, agricultural conversion, and fuel modification. CA populations have declined greatly. Reported to intergrade with ssp. zacaensis. See Madroño 1(4):86 (1922) for original description, Madroño 19:205 (1968) for revised nomenclature, and Four Seasons 7(4):5-27 (1987) for taxonomic treatment.
Threats:
Taxonomy:
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 7 February 2025].