Cercocarpus traskiae
Encyclopedia
Cercocarpus traskiae, known by the common names Santa Catalina Island mountain-mahogany and Catalina mahogany, is a rare species of plant
in the rose family
. It is endemic to the Channel Islands of California
in the United States
, where it is known from just a single population. It was rare when it was first discovered in 1897 or 1898, when about 40 to 50 plants were counted. When it was federally listed as an endangered species
in 1996 there were only six mature plants remaining. It has been called "one of the rarest shrubs in the continental United States" and "one of the rarest trees in North America."
The plants are all located in Wild Boar Gully on Santa Catalina Island
, an arroyo
covered in coastal sage scrub
. The steep sides of the arroyo contain soils of saussurite
gabbro
.
This is a large shrub
or tree
that grows up to 8 meters in height. The leaves have thick, leathery oval blades with serrated edges and woolly-haired undersides. The leathery, woolly texture of the leaves distinguishes it from other Cercocarpus. The inflorescence
is a cluster of up to 10 flowers which do not have petals. Plants do not always flower each year.
While there are sometimes many seedling
s noted, the seedling survival rate and rate of recruitment
are quite low. As of 2007, there are only seven adult trees capable of reproduction, all located in Wild Boar Gully, and most of these are very old.
The tree is threatened by ungulate
s such as deer and feral goat
s and pig
s. The goats have been removed and fencing has been placed to prevent the remaining animals from touching the plants. This rare species hybridizes with its relative, Cercocarpus betuloides
, a situation that may lead to genetic swamping
of the rare plant. This hybridization may be made more likely by the animals' disturbance of the habitat. Many of the seedlings and saplings growing today may be hybrids. The population of pure C. traskiae is not increasing and the species is entirely dependent on human intervention today.
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
in the rose family
Rosaceae
Rosaceae are a medium-sized family of flowering plants, including about 2830 species in 95 genera. The name is derived from the type genus Rosa. Among the largest genera are Alchemilla , Sorbus , Crataegus , Cotoneaster , and Rubus...
. It is endemic to the Channel Islands of California
Channel Islands of California
The Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel in the United States of America...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, where it is known from just a single population. It was rare when it was first discovered in 1897 or 1898, when about 40 to 50 plants were counted. When it was federally listed as an endangered 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...
in 1996 there were only six mature plants remaining. It has been called "one of the rarest shrubs in the continental United States" and "one of the rarest trees in North America."
The plants are all located in Wild Boar Gully on Santa Catalina Island
Santa Catalina Island, California
Santa Catalina Island, often called Catalina Island, or just Catalina, is a rocky island off the coast of the U.S. state of California. The island is long and across at its greatest width. The island is located about south-southwest of Los Angeles, California. The highest point on the island is...
, an arroyo
Arroyo (creek)
An arroyo , a Spanish word translated as brook, and also called a wash is usually a dry creek or stream bed—gulch that temporarily or seasonally fills and flows after sufficient rain. Wadi is a similar term in Africa. In Spain, a rambla has a similar meaning to arroyo.-Types and processes:Arroyos...
covered in coastal sage scrub
Coastal sage scrub
Coastal sage scrub is a low scrubland plant community found in the California chaparral and woodlands ecoregion of coastal California and northern Baja California. It is characterized by low-growing aromatic, and drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the...
. The steep sides of the arroyo contain soils of saussurite
Saussurite
Saussurite is a mineral aggregate which is formed as a hydrothermal alteration product of plagioclase feldspar. It appears very similar to zoisite with a green or grayish-green color, it has been used as a substitute or simulant for jade....
gabbro
Gabbro
Gabbro refers to a large group of dark, coarse-grained, intrusive mafic igneous rocks chemically equivalent to basalt. The rocks are plutonic, formed when molten magma is trapped beneath the Earth's surface and cools into a crystalline mass....
.
This is a large shrub
Shrub
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...
or tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
that grows up to 8 meters in height. The leaves have thick, leathery oval blades with serrated edges and woolly-haired undersides. The leathery, woolly texture of the leaves distinguishes it from other Cercocarpus. 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 cluster of up to 10 flowers which do not have petals. Plants do not always flower each year.
While there are sometimes many seedling
Seedling
thumb|Monocot and dicot seedlingsA seedling is a young plant sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle , the hypocotyl , and the cotyledons...
s noted, the seedling survival rate and rate of recruitment
Recruitment (biology)
In biology, recruitment occurs when juvenile organisms survive to be added to a population. The term is generally used to refer to a stage whereby the organisms are settled and able to be detected by an observer....
are quite low. As of 2007, there are only seven adult trees capable of reproduction, all located in Wild Boar Gully, and most of these are very old.
The tree is threatened by ungulate
Ungulate
Ungulates are several groups of mammals, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. They make up several orders of mammals, of which six to eight survive...
s such as deer and feral goat
Feral goat
The feral goat is the domestic goat when it has become established in the wild. Feral goats occur in Australia, New Zealand, Ireland, Great Britain, Hawaii, the Galapagos and in many other parts of the world...
s and pig
Pig
A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...
s. The goats have been removed and fencing has been placed to prevent the remaining animals from touching the plants. This rare species hybridizes with its relative, Cercocarpus betuloides
Cercocarpus betuloides
Cercocarpus betuloides, California Mountain Mahogany, is a species in the family Rosaceae. It typically grows in dry areas in the foothills and mountains of California, often in chaparral communities, and in other parts of the Southwestern United States and Baja California.-Description:This shrub...
, a situation that may lead to genetic swamping
Genetic pollution
Genetic pollution is a controversial term for uncontrolled gene flow into wild populations. This gene flow is undesirable according to some environmentalists and conservationists, including groups such as Greenpeace, TRAFFIC, and GeneWatch UK.-Usage:...
of the rare plant. This hybridization may be made more likely by the animals' disturbance of the habitat. Many of the seedlings and saplings growing today may be hybrids. The population of pure C. traskiae is not increasing and the species is entirely dependent on human intervention today.
External links
- World Conservation Monitoring Centre 1998. Cercocarpus traskiae. 2010 IUCN Red List of Threatened Species. Downloaded on 30 January 2011.
- Jepson Manual Treatment
- USDA Plants Profile
- Photo gallery