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Ceanothus impressus

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Santa Barbara Ceanothus

G3Vulnerable Found in 1 roadless area NatureServe Explorer →
G3VulnerableGlobal Rank
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.132820
Element CodePDRHA040L0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRhamnales
FamilyRhamnaceae
GenusCeanothus
Other Common Names
Santa Barbara Buckbrush (EN) Santa Barbara ceanothus (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2019-06-26
Change Date2019-06-26
Edition Date2021-04-20
Edition AuthorsTreher (2019, 2021)
Threat ImpactMedium
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Ceanothus impressus is endemic to the Central Coast region of California in the western United States. There are two varieties recognized: variety impressus occurs in western Santa Barbara County and variety nipomensis occurs in Santa Barbara and San Luis Obispo Counties. Both varieties are threatened by development, road and trail construction, and invasive species. Field surveys are needed to better understand the abundance, distribution, and threats of these varieties.
Range Extent Comments
Ceanothus impressus is endemic to the Central Coast region of California in the western United States. There are two varieties recognized: Ceanothus impressus var. impressus occurs in western Santa Barbara County and var. nipomensis occurs in Santa Barbara and San Luis Obispo Counties (Wilken and Burge 2016). Ceanothus impressus var. nipomensis is the most restricted of the two, which is found on the Irish Hills and Nipomo Mesa (Wilken and Burge 2016).
Occurrences Comments
There are 14 occurrences of Ceanothus impressus var. nipomensis and 37 occurrences known for Ceanothus impressus var. impressus. A number of occurrences are on private land where there is significant development pressure.
Threat Impact Comments
Threats are not well known for this species, but development is likely one of the most severe threats. Potential threats include non-native plants, road and trail construction and maintenance (CNPS 2019).
Ecology & Habitat

Habitat

This taxon grows on sandy mesas and sandstone hills and slopes, often in burned areas. It grows in chaparral, including maritime chaparral communities, in which woollyleaf manzanita (Arctostaphylos tomentosa ssp. tomentosa) is common, as well as communities just inland from shifting coastal sand dunes. It is also sometimes found in Bishop pine forest. Ceanothus impressus is found at a maximum of 320 m elevation.
Terrestrial Habitats
Forest/WoodlandForest - ConiferShrubland/chaparralSand/dune
Other Nations (1)
United StatesN3
ProvinceRankNative
CaliforniaSNRYes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentLarge - restrictedExtreme - moderateHigh (continuing)
1.1 - Housing & urban areasLarge - restrictedExtreme - moderateHigh (continuing)
1.3 - Tourism & recreation areasUnknownUnknownHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownHigh (continuing)

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Plant Characteristics
Economic Value (Genus)Yes
Roadless Areas (1)
California (1)
AreaForestAcres
Garcia MountainLos Padres National Forest7,850
References (11)
  1. CalFlora. 2005. Information on California plants for education, research and conservation. Berkeley, California: The CalFlora Database [web application]. Available: http://www.calflora.org/. (Accessed 2005)
  2. California Native Plant Society (CNPS). 2021. Calscape. Online. Available: <a href="https://calscape.org/">https://calscape.org/</a> (accessed: 2021).
  3. Flora of North America Editorial Committee (FNA). 2016. Flora of North America north of Mexico. Vol. 12. Magnoliophyta: Vitaceae to Garryaceae. Oxford Univ. Press, New York. xxiv + 603 pp.
  4. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  5. Hoover, R.F. 1970. The vascular plants of San Luis Obispo County, California. Univ. California Press, Berkeley. 350 pp.
  6. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  7. Munz, P.A., with D.D. Keck. 1959. A California flora. Univ. California Press, Berkeley. 1681 pp.
  8. Sawyer, J.O. and T. Keeler-Wolf. 1995. A Manual of California Vegetation. California Native Plant Society, Sacramento.
  9. Smith, C.F. 1998. A flora of the Santa Barbara region, California. 2nd edition. Santa Barbara Botanic Garden and Capra Press, Santa Barbara. 391 pp.
  10. USDA, Natural Resources Conservation Service, PLANTS Database [USDA PLANTS]. http://plants.usda.gov/. Accessed 2015.
  11. Wilken, D.H., and D.O. Burge. 2016. <i>Ceanothus impressus</i>, in Jepson Flora Project (eds.) <em>Jepson eFlora</em>, Revision 4, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=18459 (accessed July 01, 2019).