Hybrids: Vail Lake ceanothus hybridizes with hoaryleaf ceanothus (C. crassifolius) where the 2 species occur together. Because hoaryleaf ceanothus is not adapted to the gabbroic soils to which Vail Lake ceanothus is endemic, viability of these hybrids may be poor [13,16].SYNONYMS:
|Distribution of Vail Lake ceanothus. Map courtesy of the Jepson Herbarium .|
Vail Lake ceanothus has a narrow geographical range, occurring in the Peninsular Ranges geographical province. It is a narrow endemic in the southwestern region of California [2,12]. It is known from 4 occurrences: 1 near Vail Lake, California, and 3 in the Agua Tibia Wilderness of the Cleveland National Forest, southern Riverside County [3,5,9,13]. Populations are separated by <3.5 miles (5.6 km ), and the species occupies <50 total acres (20 ha) .
States: CA 
Site Characteristics: Vail Lake ceanothus occurs on dry sites, including ridgetops and north- to northeast-facing rocky slopes, dry canyons, and stream edges. It only grows on shallow, phosphorus-deficient soils derived from weathered gabbro [2,9,10,12,13,16].
Vail Lake ceanothus occurs at 2,000 to 3,000 feet (600-900 m) elevation [2,10,12,13,16].Plant Communities: Vail Lake ceanothus grows in chaparral communities dominated or codominated by chamise (Adenostoma fasciculatum) . The Fire Regime Table lists the single plant community in which Vail Lake ceanothus may occur and provides some information on its fire regime.
Seasonal Development: Vail Lake ceanothus flowers from February to March, with seeds maturing from May to June .
Regeneration: Vail Lake ceanothus establishes only from seed [2,9]. Seeds are stored in the soil seed bank. They may remain dormant for long periods, requiring heat or mechanical scarification to germinate [9,13].
Postfire regeneration strategy :
Shrub without adventitious buds and without a sprouting root crown
Ground residual colonizer (on site, initial community)
Secondary colonizer (on- or off-site seed sources)
Fire adaptations and postfire response: Vail Lake ceanothus establishes from soil-stored seed after fire. It cannot sprout from the root crown after fire . Vail Lake ceanothus requires 10 to 20 years after fire to replenish its seed bank (Keeley 1992 personal communication cited in ). Short fire-return intervals can reduce populations of Vail Lake ceanothus, preventing maturity and seed production [10,13]. Hairy ceanothus (C. oliganthus), a similar chaparral species, was almost eliminated in an area that burned twice within 2 years .
As of 2012, only 1 study was available on the fire ecology of Vail Lake ceanothus. The study reports monitoring data from the 2000 Pechanga Wildfire on the Cleveland National Forest, part of which had burned in the 1989 Vail Wildfire. Monitoring was conducted in autumn 2001 and 2002. Some seedlings were present 2 years after fire despite “extreme drought conditions” in postfire years 1 and 2. Seedling recruitment was lowest in twice-burned plots; however, differences between once-burned and twice-burned plots were not considered statistically significant. The author speculated the seed bank was probably less abundant in the twice-burned than once-burned plots. Off-site seed from adjacent live plants is expected to aid in the postfire recovery of Vail Lake ceanothus .
|Postfire density of Vail Lake ceanothus on once- or twice-burned sites |
|Site||Burned 1× or 2×||2001 density
|1||Once, 2000 Pechanga Wildfire||3.79||4.76||+25|
|2||Once, 2000 Pechanga Wildfire||0.92||1.54||+67|
|3||Twice, 1989 Vail Wildfire & 2000 Pechanga Wildfire||0.69||0.4||-29|
Some plants were flowering and producing seed by postfire year 2, but some seedling mortality of Vail Lake ceanothus was noted as well (6, 7, and 1 plants on Sites 1, 2, and 3, respectively). If continued monitoring shows further decline in seedling density on twice-burned plots, Davis  suggested that seed collection and planting be considered to augment postfire recovery of Vail Lake ceanothus.
Further research is needed on the fire and basic ecology of Vail Lake ceanothus.
Legal status and management:
Federal leagal status:
Other status and management:
Vail Lake ceanothus is endangered in the state of California .
Long-term hybridization of Vail Lake ceanothus with hoaryleaf ceanothus may be detrimental to Vail Lake ceanothus populations [4,9]. It is also threatened by residential development and construction of fuel breaks for use in fire suppression. Mitigation of development effects is planned in the joint USDA Forest Service, USDI Fish and Wildlife Service, and California Department of Fish and Game conservation strategy for coastal sage scrub and in the Western Riverside Multiple Species Habitat Conservation Plan [3,13].
|Fire regime information on the vegetation community in which Vail Lake ceanothus occurs. This information is taken from the LANDFIRE Rapid Assessment Vegetation Model , which was developed by local experts using available literature. This table summarizes fire regime characteristics for the plant community listed. The PDF file linked from that plant community name describes the model and synthesizes the knowledge available on vegetation composition, structure, and dynamics in that community.|
|Vegetation Community (Potential Natural Vegetation Group)||Fire severity*||Fire regime characteristics|
|Percent of fires||Mean interval
Replacement: Any fire that causes greater than 75% top removal of a vegetation-fuel type, resulting in general replacement of existing vegetation; may or may not cause a lethal effect on the plants.
Mixed: Any fire burning more than 5% of an area that does not qualify as a replacement, surface, or low-severity fire; includes mosaic and other fires that are intermediate in effects.
Surface or low: Any fire that causes less than 25% upper layer replacement and/or removal in a vegetation-fuel class but burns 5% or more of the area [1,6].
1. Barrett, S.; Havlina, D.; Jones, J.; Hann, W.; Frame, C.; Hamilton, D.; Schon, K.; Demeo, T.; Hutter, L.; Menakis, J. 2010. Interagency Fire Regime Condition Class Guidebook. Version 3.0, [Online]. In: Interagency Fire Regime Condition Class (FRCC). U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior; The Nature Conservancy (Producers). Available: http://www.frcc.gov/. 
2. Boyd, Steve; Ross, Timothy; Arnseth, Laurel. 1991. Ceanothus ophiochilus (Rhamanaceae): a distinctive, narrowly endemic species from Riverside County, California. Phytologia. 70(1): 28-41. 
3. California Department of Fish and Game, Habitat Conservation Planning Branch. 2005. The status of rare, threatened, and endangered plants and animals of California 2000-2004, [Online]. In: California's plants and animals. Sacramento, CA: Habitat Conservation Planning Branch (Producer). Available: http: //www.dfg.ca.gov/hcpb/species/t_e_spp/ann_te_rpt.shtml [2006, February 6]. 
4. California Native Plant Society. 2012. Inventory plant detail: Ceanothus ophiochilus, [Online]. In: Inventory of rare and endangered plants. Version v8-01a. Sacramento, CA: California Native Plant Society (Producer). Available: http://www.rareplants.cnps.org/detail/1615.html [2012, October 3]. 
5. Davis, Linh. 2003. Vail Lake ceanothus: Post fire monitoring report. Post Fire Recruitment Monitoring Report. San Diego, CA: U.S. Department of Agriculture, Forest Service, Cleveland National Forest. 4 p. 
6. LANDFIRE Rapid Assessment. 2005. Reference condition modeling manual (Version 2.1), [Online]. In: LANDFIRE. Cooperative Agreement 04-CA-11132543-189. Boulder, CO: The Nature Conservancy; U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior (Producers). 72 p. Available: http://www.landfire.gov/downloadfile.php?file=RA_Modeling_Manual_v2_1.pdf [2007, May 24]. 
7. LANDFIRE Rapid Assessment. 2007. Rapid assessment reference condition models, [Online]. In: LANDFIRE. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Lab; U.S. Geological Survey; The Nature Conservancy (Producers). Available: http://www.landfire.gov/models_EW.php [2008, April 18] 
8. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
9. Shaffer, Kevin. 1993. Report to the Fish and Game Commission on the status of Vail Lake ceanothus (Ceanothus ophiochilus). Status Report #93-3. Sacramento, CA: California Department of Fish and Game, Natural Heritage Division. 31 p. 
10. Stephenson, John R.; Calcarone, Gena M. 1999. Southern California mountains and foothills assessment. Gen. Tech. Rep. PSW-GTR-172. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 402 p. 
11. Stickney, Peter F. 1989. Seral origin of species comprising secondary plant succession in northern Rocky Mountain forests. FEIS workshop: Postfire regeneration. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 10 p. 
12. The Jepson Herbarium. 2012. Jepson online interchange for California floristics, [Online]. In: Jepson Flora Project. Berkeley, CA: University of California, The University and Jepson Herbaria (Producers). Available: http://ucjeps.berkeley.edu/interchange.html 
13. U.S. Department of Agriculture, Forest Service, Pacific Southwest Region. 2005. Species account: Ceanothus ophiochilus. In: Reading room--Species accounts-plants. In: Revised Land Management Plans and Final Environmental Impact Statement: Angeles National Forest, Cleveland National Forest, Los Padres National Forest, San Bernardino National Forest. R5-MB-086-CD [CD ROM]. Vallejo, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Region (Producer). On file with: U.S. Department of Agriculture, Forest Service, Cleveland National Forest. 
14. U.S. Department of Agriculture, Natural Resources Conservation Service. 2012. PLANTS Database, [Online]. Available: http://plants.usda.gov/. 
15. U.S. Department of the Interior, Fish and Wildlife Service. 2016. Endangered Species Program, [Online]. Available: http://www.fws.gov/endangered/. 
16. U.S. Department of the Interior, Fish and Wildlife Service. 1998. Endangered and threatened wildlife and plants: Endangered or threatened status for three plants from the chaparral and scrub of southwestern California, [Online]. Final Rule: Federal Register: October 13, 1998. Volume 63: No. 197: 54956-54971. Sacramento, CA: California Department of Pesticide Regulation, Endangered Species Project (Producer). Available: http://www.cdpr.ca.gov/docs/endspec/estext/fb101398.txt [2012, October 3]. 
17. Zedler, Paul H.; Gautier, Clayton R.; McMaster, Gregory S. 1983. Vegetation change in response to extreme events: the effect of a short interval between fires in California chaparral and coastal scrub. Ecology. 64(4): 809-818.