''Arctostaphylos pallida'', commonly known as pallid manzanita, Oakland Hills manzanita, and Alameda manzanita, is an upright

manzanita Manzanita is a common name for many species of the genus ''Arctostaphylos''. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from Southern British Columbia and Washington to Or ...

shrub from the

Ericaceae The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it th ...

, or heath family. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the eastern

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

of Northern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Description

''Arctostaphylos pallida'' grows to around in height. The branches on the shrub are reddish or grayish (more reddish) and they have twigs that tend to be bristly. The ovate to triangular leaves are bristly, strongly overlapping and clasping. They are 1.0 to long and 0.8 to wide. The dense, white flowers are urn-shaped and 0.2 to long. The flowering period is from November to March. ''A. pallida'' commonly co-occurs with another manzanita species, brittle leaf manzanita (''

Arctostaphylos tomentosa ''Arctostaphylos tomentosa'' is a species of manzanita known by the common name woollyleaf manzanita or woolley manzanita. This shrub is endemic to California. It is a resident of chaparral canyons, foothills, and lower-elevation mountains. On ...

'' ssp. ''crustacea''), but the latter is a

burl A burl (American English) or burr (British English) is a tree growth in which the grain has grown in a deformed manner. It is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from do ...

-forming species with spreading leaves. ''A. pallida'' does not form burls.

Distribution

The species is found from in elevation, primarily on thin soils composed of

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

and

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

. The plants are found in manzanita chaparral habitat of the montane chaparral and woodlands ecosystem, and is frequently surrounded by oak woodlands and other

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

shrubs. ;Endemism ''Arctostaphylos pallida'' is known from approximately 13 populations in

Alameda An alameda is a Avenue (landscape), street or path lined with trees () and may refer to: Places Canada *Alameda, Saskatchewan, town in Saskatchewan **Grant Devine Dam, formerly ''Alameda Dam'', a dam and reservoir in southern Saskatchewan Chile ...

and Contra Costa counties.The Nature Conservancy
/ref> The two largest populations, which are owned by the

East Bay Regional Park District The East Bay Regional Park District (EBRPD) is a special district operating in Alameda County and Contra Costa County, California, within the East Bay area of the San Francisco Bay Area. It maintains and operates a system of regional parks which ...

, are located at Huckleberry Ridge—

Huckleberry Botanic Regional Preserve Huckleberry Botanic Regional Preserve is a regional park and nature reserve in the Oakland Hills, in the eastern East Bay (San Francisco Bay Area) region of the San Francisco Bay Area of California. It is within Alameda and Contra Costa Counti ...

in Alameda and Contra Costa Counties and at

Sobrante Ridge Regional Park Sobrante Ridge Regional Park, or simply Sobrante Ridge, is a regional park of the East Bay Regional Parks District The East Bay Regional Park District (EBRPD) is a special district operating in Alameda County and Contra Costa County, California, w ...

in Contra Costa County. Several other small, natural and planted populations occur in Alameda and Contra Costa counties. The two largest groups occupy an area of approximately . These two populations are found in maritime sage and chaparral, a habitat with mesic soil conditions and a maritime influence. Many smaller populations occur in coastal scrub.Pallid Manzanita species account from the Sacramento Fish & Wildlife Office

Threats

The primary threats to the species are the effects of

fire suppression Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts in wild land areas require different techniques, equipment, and training from the more familiar structure fire fighting found in populated a ...

, and shading and competition from

native plant In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equ ...

s, and introduced and

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

. To a lesser extent, the species is threatened by fungal infection, herbicide spraying, hybridization, construction of

road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

s, and the ongoing effects of

habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes ...

and loss. This is a federally listed

threatened species Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...

. It was listed as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

by the

California Department of Fish and Game The California Department of Fish and Wildlife (CDFW), formerly known as the California Department of Fish and Game (CDFG), is a state agency under the California Natural Resources Agency. The Department of Fish and Wildlife manages and protect ...

in November 1997. The

California Native Plant Society The California Native Plant Society (CNPS) is a California environmental non-profit organization (501(c)3) that seeks to increase understanding of California's native flora and to preserve it for future generations. The mission of CNPS is to con ...

has placed it on List 1B (rare or endangered throughout its range).

References

External links

Jepson Manual Treatment: ''Arctostaphylos pallida''USDA Plants Profile - ''Arctostaphylos pallida'' (Alameda manzanita)''Arctostaphylos pallida'' - U.C. Photo gallery
{{DEFAULTSORT:Arctostaphylos Pallida pallida Endemic flora of California Endemic flora of the San Francisco Bay Area Natural history of the California chaparral and woodlands ~ Natural history of Alameda County, California Natural history of Contra Costa County, California

Description

Distribution

Threats

See also

References

External links