Taxon Report
Arctostaphylos rudis Jeps. & Wies.sand mesa manzanita |
 © 2022 David J. Keil |
Taxon Summary
Arctostaphylos rudis, commonly known as sand mesa manzanita, is a perennial evergreen shrub in the Ericaceae that is found only in California. It occurs within Chaparral (maritime), and Coastal scrub, growing at elevations from 25 to 322 meters. Arctostaphylos rudis is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.Classification
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Scientific Name: |
Arctostaphylos rudis Jeps. & Wies. |
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Common Name: |
sand mesa manzanita |
| Family: | Ericaceae |
| Element Code: | PDERI043E0 |
| USDA Plants Symbol: | ARRU2 |
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Synonyms/Other Names: |
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Ecology and Life History
| Lifeform: | perennial evergreen shrub |
| Blooming Period: Nov-Feb | Nov-Feb |
| Elevation: | 25-322 (80-1055) |
| General Habitats: | Chaparral, Coastal scrub |
| Microhabitat: | Sandy |
| Microhabitat Details: |
Conservation Status
| CA Rare Plant Rank: | 1B.1 |
| Global Rank: | G2 |
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State Rank: |
S2 |
| State List: | None |
| Fed List: | None |
| Other Status: | BLM_S; SB_SBBG |
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CRPR Changes: |
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Occurrence Data from the CNDDB
| Total Occurrences: | 24 |
| Element Occurrence Ranks: | |
| Excellent (A) | 4 |
| Good (B) | 6 |
| Fair (C) | 1 |
| Poor (D) | 1 |
| None (X) | 0 |
| Unknown (U) | 12 |
| California Endemic: True | |
| California Counties and Islands: Name (Code) | |
| Santa Barbara (SBA) | |
| Quads: Name (Quad Code) | |
| Casmalia (3412075), Guadalupe (3412085), Lompoc (3412064), Lompoc Hills (3412054), Los Alamos (3412063), Orcutt (3412074), Point Arguello (3412056), Point Sal (3412086), Sisquoc (3412073), Surf (3412065), Tranquillon Mtn. (3412055) | |
Threat List Data from the CNDDB
| Threat List Total: | 8 | |
| EOs with Threat Listed: | Total EOs | % of EOs |
| 10 | 42 % | |
| Development | 7 | 29% |
| Non-native plant impacts | 4 | 16% |
| Other | 3 | 12% |
| Road/trail construction/maint. | 2 | 8% |
| Improper burning regime | 2 | 8% |
| Grazing | 1 | 4% |
| Vandalism/dumping/litter | 1 | 4% |
| Wood cutting or brush clearing | 1 | 4% |
Notes
| Plants on Nipomo Mesa (SLO Co.) have been determined to be a novel species, A. nipumu, with A. rudis becoming restricted to SBA Co. |
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Threats: |
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Threatened by development, agriculture, oil extraction, and road construction and maintenance. |
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Taxonomy: |
| Differentiated from A. nipumu by bark differences and presence of a basal burl. For additional information, see key provided in the A. nipumu original description (Phytokeys 251: 119-142 (2025)) |
Selected References
| Erythea 8:100-101 (1938) |
Citation
California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 5 November 2025].