Arctostaphylos myrtifolia
Encyclopedia
Arctostaphylos myrtifolia is a rare species of manzanita
known by the common name Ione manzanita. It is endemic to the Sierra Nevada foothills of California
. It grows in the chaparral
and woodland plant community on a distinctive acidic soil series in western Amador
and Calaveras Counties
. There are only about 17 occurrences, but the plant is abundant in some areas of its limited range. This is a federally listed threatened species
.
reaching just over a meter in maximum height. The small bright green leaves are coated in tiny glandular hairs and are shiny but rough in texture. They are less than 2 centimeters long. The inflorescence
is a raceme
of urn-shaped manzanita flowers on bright red branches. The fruit is a cylindrical drupe
only a few millimeters long.
, including F. aesculi
, causes some mortality, and root and crown rot caused by Phytophthora cinnamomi
has destroyed entire stands of the manzanita and prevented its regrowth in patches of infested soil. These microorganisms, as well as a newly identified one, Phytophthora cambivora
, are spreading rapidly and may soon reach the entire range of the plant's distribution. Because of this threat, which may lead to the extinction
of the species, the United States Fish and Wildlife Service
has recommended that it be upgraded from threatened to endangered status
.
Arctostaphylos
Arctostaphylos is a genus of plants comprised by the manzanitas and bearberries. They are shrubs or small trees.There are about 60 species of Arctostaphylos, ranging from ground-hugging arctic, coastal, and mountain species to small trees up to 6 m tall. Most are evergreen , with small oval...
known by the common name Ione manzanita. It is endemic to the Sierra Nevada foothills of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. It grows in the chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
and woodland plant community on a distinctive acidic soil series in western Amador
Amador County, California
Amador County is a county located in the Sierra Nevada of the U.S. state of California. As of the 2010 census, the population was 38,091. The county seat is Jackson.Amador County bills itself as "The Heart of the Mother Lode" and lies within the Gold Country...
and Calaveras Counties
Calaveras County, California
Calaveras County is a county located in the Gold Country of the U.S. state of California. Calaveras is the Spanish word for skulls; the county was reportedly named for the remains of Native Americans discovered by the Spanish explorer Captain Gabriel Moraga. As of the 2010 census, the county had a...
. There are only about 17 occurrences, but the plant is abundant in some areas of its limited range. This is a federally listed threatened species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
.
Description
Arctostaphylos myrtifolia is a red-barked, bristly shrubShrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
reaching just over a meter in maximum height. The small bright green leaves are coated in tiny glandular hairs and are shiny but rough in texture. They are less than 2 centimeters long. The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
of urn-shaped manzanita flowers on bright red branches. The fruit is a cylindrical drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...
only a few millimeters long.
Conservation
A major threat to this rare endemic plant is a pair of fungal diseases. A branch canker caused by species of FusicoccumFusicoccum
Fusicoccum is a genus of anamorphic fungi in the family Botryosphaeriaceae. There are over 90 species.-Species:*F. abietis*F. acaciae*F. aceris*F. advenum*F. aesculanum*F. africanum*F. albiziae*F. album...
, including F. aesculi
Fusicoccum aesculi
Fusicoccum aesculi is a fungus. It is a plant pathogen.- External links :**...
, causes some mortality, and root and crown rot caused by Phytophthora cinnamomi
Phytophthora cinnamomi
Phytophthora cinnamomi is a soil-borne water mould that produces an infection which causes a condition in plants called root rot or dieback. The plant pathogen is one of the world's most invasive species and is present in over 70 countries from around the world.- Life cycle and effects on plants :P...
has destroyed entire stands of the manzanita and prevented its regrowth in patches of infested soil. These microorganisms, as well as a newly identified one, Phytophthora cambivora
Phytophthora cambivora
Phytophthora cambivora is a plant pathogen that causes Ink disease in European Chestnut trees . Ink disease, also caused by Phytophthora cinnamomi, is thought to have been present in Europe since the 18th century and causes chestnut trees to wilt and die, major epidemics occurred during the 19th...
, are spreading rapidly and may soon reach the entire range of the plant's distribution. Because of this threat, which may lead to the extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
of the species, the United States Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
has recommended that it be upgraded from threatened to endangered status
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
.
See also
- California chaparral and woodlandsCalifornia chaparral and woodlandsThe California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
- California interior chaparral and woodlandsCalifornia interior chaparral and woodlandsThe California interior chaparral and woodlands ecoregion covers in an elliptical ring around the California Central Valley. It occurs on hills and mountains ranging from to . It is part of the Mediterranean forests, woodlands, and scrub biome, with cool, wet winters and hot, dry summers...