Castilleja grisea
Encyclopedia
Castilleja grisea is a rare species of Indian paintbrush
known by the common name San Clemente Island Indian paintbrush. It is endemic to San Clemente Island
, one of the Channel Islands of California
. San Clemente Island is owned by the US Navy so the Navy is involved in a management program to recover this species.
is made up of layers of bracts one to two centimeters long, gray-green in color at the bases and tipped with greenish yellow. Between the bracts emerge dull yellow pouched flowers. The fruit is a capsule about a centimeter long containing tiny seeds with netted surfaces.
s which were introduced there. The island was also used for grazing sheep and cattle
, and some feral pigs were present. The animals may have eaten the plant at times, but they mainly damaged the land by trampling the soil, which led to soil compaction
, loss of topsoil
, and erosion
. The introduction
of exotic plant species such as ripgut brome
(Bromus diandrus), wild oat
(Avena barbata), and red brome
(Bromus madritensis rubus) also degraded the habitat.
Due to sttep terrain of San Clemente Island the exact abundance of Castilleja grisea is not currently known. Recent surveys have discovered new populations of this species. Surveys in 2007 estimate more than 10,000 plants existing. This plant has been a federally listed endangered species
since 1977, when it was one of the first species to be designated so. The plant's population had been drastically reduced by the activity of the feral goats. Its populations has increased at least ten-fold since the removal of these non-native herbivores. The species has recovered so well through management programs by the Navy, it was recommended for downlisting during the last review conducted by the United States Fish and Wildlife Service. Remaining threats include erosion, invasive grasses, and wildfire
from military exercise
s.
The species has a relatively high genetic variability
for an uncommon island endemic. This and its steady recovery from low numbers give an optimistic outlook for the species' recovery.
Castilleja
Castilleja, commonly known as Indian paintbrush or Prairie-fire, is a genus of about 200 species of annual and perennial herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and one species as far west as the Kola Peninsula in Siberia...
known by the common name San Clemente Island Indian paintbrush. It is endemic to San Clemente Island
San Clemente Island
San Clemente Island is the southernmost of the Channel Islands of California. It is owned and operated by the United States Navy, and is a part of Los Angeles County. Defined by the United States Census Bureau as Block Group 2 of Census Tract 5991 of Los Angeles County, California, it is long and...
, one of 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...
. San Clemente Island is owned by the US Navy so the Navy is involved in a management program to recover this species.
Description
The San Clemente Island Indian paintbrush is a perennial herb coated densely in long gray hairs. The highly branching stem grows 40 to 60 centimeters tall and bears linear leaves each a few centimeters long. The inflorescenceInflorescence
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 made up of layers of bracts one to two centimeters long, gray-green in color at the bases and tipped with greenish yellow. Between the bracts emerge dull yellow pouched flowers. The fruit is a capsule about a centimeter long containing tiny seeds with netted surfaces.
Distribution
This species was once considered to be "relatively common" on its home island. Since then the habitat has been severely degraded, mainly by feral goatFeral 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 which were introduced there. The island was also used for grazing sheep and cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
, and some feral pigs were present. The animals may have eaten the plant at times, but they mainly damaged the land by trampling the soil, which led to soil compaction
Soil compaction
In Geotechnical engineering, soil compaction is the process in which a stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water being displaced from between the soil grains then...
, loss of topsoil
Topsoil
Topsoil is the upper, outermost layer of soil, usually the top to . It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.-Importance:...
, and erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
. The introduction
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
of exotic plant species such as ripgut brome
Bromus diandrus
Bromus diandrus is a species of grass known by the common names great brome and "ripgut brome".This is a brome grass which is native to the Mediterranean but has been introduced to much of the rest of the world...
(Bromus diandrus), wild oat
Avena barbata
Avena barbata is a species of wild oat known by the common name slender wild oat. It has edible seeds. It is native to central Asia and the Mediterranean Basin. It is also known in North America as an introduced species and noxious weed. It is widespread in California, where it has displaced native...
(Avena barbata), and red brome
Bromus madritensis
Bromus madritensis is a species of brome grass known by the common name compact brome.It is native to Europe but it has been widely introduced elsewhere, such as North America, where it is found in many areas. It is now known nearly worldwide...
(Bromus madritensis rubus) also degraded the habitat.
Due to sttep terrain of San Clemente Island the exact abundance of Castilleja grisea is not currently known. Recent surveys have discovered new populations of this species. Surveys in 2007 estimate more than 10,000 plants existing. This plant has been a federally listed 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...
since 1977, when it was one of the first species to be designated so. The plant's population had been drastically reduced by the activity of the feral goats. Its populations has increased at least ten-fold since the removal of these non-native herbivores. The species has recovered so well through management programs by the Navy, it was recommended for downlisting during the last review conducted by the United States Fish and Wildlife Service. Remaining threats include erosion, invasive grasses, and wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
from military exercise
Military exercise
A military exercise is the employment of military resources in training for military operations, either exploring the effects of warfare or testing strategies without actual combat...
s.
The species has a relatively high genetic variability
Genetic variability
Genetic variability is a measure of the tendency of individual genotypes in a population to vary from one another. Variability is different from genetic diversity, which is the amount of variation seen in a particular population. The variability of a trait describes how much that trait tends to...
for an uncommon island endemic. This and its steady recovery from low numbers give an optimistic outlook for the species' recovery.