''Arctostaphylos rainbowensis'' is a species of manzanita known by the common name Rainbow manzanita. 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 ...

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 ...

, where it is known only from northern

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the List of United States cities by population, eigh ...

and southern Riverside Counties in the

Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, which ...

.Calflora database: ''Arctostaphylos rainbowensis''
. accessed 2.2.2013 It was named for the community of

Rainbow, California Rainbow is a census designated place (CDP) in northern San Diego County in the U.S. state of California. The population was 1,832 at the 2010 census, down from 2,026 at the 2000 census. Geography Rainbow is located at (33.411213, -117.149209) ...

, near where it is most common in the

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 ...

of the lower elevation coastal

Santa Ana Mountains The Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately southeast of the Los Angeles Basin largely along the border between Orange and Riverside co ...

, and the only manzanita species throughout most of its range.

Taxonomy

A specimen was first collected in 1973 and considered to be part of a disjunct population of ''Arctostaphylos peninsularis'', or alternately a

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

between ''

Arctostaphylos glauca ''Arctostaphylos glauca'' is a species of manzanita known by the common name bigberry manzanita. It is native to California and Baja California, where it grows in the chaparral and woodland of coastal and inland hills. Description ''Arctostaphy ...

'' and ''

Arctostaphylos glandulosa ''Arctostaphylos glandulosa'', with the common name Eastwood's manzanita, is a species of manzanita. Distribution This shrub is native to the coastal slopes of western North America from Oregon through California to Baja California. Descriptio ...

''.Keeley, J. E. & A. Massihi. (1994)
''Arctostaphylos rainbowensis'', a new burl-forming manzanita from San Diego County, California.
''Madroño'' 41:1 1-12. Following phenetic analyses both possibilities were discarded and the plant was described as a new species in 1994.

Description

''Arctostaphylos rainbowensis'' is an erect

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

reaching a bush-like to a tree-like in height. It produces a burl at its base and is coated in reddish brown, smooth bark. The oval leaves are up to 5 centimeters long and 3.5 wide and are hairless and somewhat waxy in texture. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a hanging cluster of white urn-shaped flowers each about 6 to 8 millimeters long. The fruit is about a centimeter wide and ripens to a dark purple-brown. ;Extirpation Since the species was first collected its habitat has undergone extensive development, leading to the

extirpation Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

of many of its populations.

Taxonomy

Description

See also

References

External links