Euphorbia skottsbergii
Encyclopedia
Euphorbia skottsbergii (syn.
Chamaesyce skottsbergii) is a rare species of flowering plant in the euphorb family
known by the common names coastal sandmat and Skottsberg's broomspurge. It is endemic to Hawaii
, where it is found in coastal shrublands
on Oahu
, Molokai
, Maui
, and Kahoolawe
. Like other Hawaiian euphorbs, this plant is known locally as akoko.
The taxonomy
of this plant is still being studied; the name and number of varieties have changed over the years and are still in flux. In 1982 the rare variety kalaeloana was added to the endangered species list
of the United States. This plant was and still is known only from Oahu's Ewa Plains between Kalaeloa
(Barber's Point) and Pearl Harbor
. It had been reduced in population by a number of factors, including Navy
activity, pollution
, destruction by bulldozer
on private property, quarry
ing, agriculture
, fire
, development and construction of housing, roads, an oil refinery
, and resort property, and expansion of the harbor
. The plant's human-caused decline probably started with the arrival of the Polynesians
. Other threats include non-native plant species
, especially kaunaoa pehu (Cassytha filiformis), kiawe
(Prosopis pallida), Chinese violet
(Asystasia gangetica), and buffel grass (Cenchrus ciliaris). Potentially damaging insect
s that visit the plant include croton moth (Aechaea janata) and spiraling whitefly (Aleurodicus dispersus).
Genetic analyses
has led to recent changes in taxonomy. The rare var. kalaeloana is now called var. skottsbergii. The populations of the plant that grow on Molokai are genetically more different from var. skottsbergii than from the more common var. vaccinioides, and have been named var. audens. Furthermore, the endangered variety on Oahu is different enough that it should probably be named a new species.
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
Chamaesyce skottsbergii) is a rare species of flowering plant in the euphorb family
Euphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
known by the common names coastal sandmat and Skottsberg's broomspurge. It is endemic to Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
, where it is found in coastal shrublands
Hawaiian tropical low shrublands
The Hawaiian tropical low shrublands are a tropical savanna ecoregion in the Hawaiian Islands. These shrublands cover an area of in the leeward lowlands of the main islands and most of the smaller islands, including the Northwestern Hawaiian Islands. The ecoregion includes both grasslands and...
on Oahu
Oahu
Oahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands and most populous of the islands in the U.S. state of Hawaii. The state capital Honolulu is located on the southeast coast...
, Molokai
Molokai
Molokai or Molokai is an island in the Hawaiian archipelago. It is 38 by 10 miles in size with a land area of , making it the fifth largest of the main Hawaiian Islands and the 27th largest island in the United States. It lies east of Oahu across the 25-mile wide Kaiwi Channel and north of...
, Maui
Maui
The island of Maui is the second-largest of the Hawaiian Islands at and is the 17th largest island in the United States. Maui is part of the state of Hawaii and is the largest of Maui County's four islands, bigger than Lānai, Kahoolawe, and Molokai. In 2010, Maui had a population of 144,444,...
, and Kahoolawe
Kahoolawe
Kahoolawe is the smallest of the eight main volcanic islands in the Hawaiian Islands. Kahoolawe is located about seven miles southwest of Maui and also southeast of Lanai, and it is long by wide, with a total land area of . The highest point on Kahoolawe is the crater of Lua Makika at the...
. Like other Hawaiian euphorbs, this plant is known locally as akoko.
The taxonomy
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
of this plant is still being studied; the name and number of varieties have changed over the years and are still in flux. In 1982 the rare variety kalaeloana was added to the endangered species list
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
of the United States. This plant was and still is known only from Oahu's Ewa Plains between Kalaeloa
Kalaeloa, Hawai'i
Kalaeloa is a census-designated place in Honolulu County, Hawaii, United States. The population was 67 at the 2000 census. The community occupies the location of the former Naval Air Station Barbers Point, which was closed in 1999 and subsequently transferred to the State of Hawaii...
(Barber's Point) and Pearl Harbor
Pearl Harbor
Pearl Harbor, known to Hawaiians as Puuloa, is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet...
. It had been reduced in population by a number of factors, including Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
activity, pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
, destruction by bulldozer
Bulldozer
A bulldozer is a crawler equipped with a substantial metal plate used to push large quantities of soil, sand, rubble, etc., during construction work and typically equipped at the rear with a claw-like device to loosen densely-compacted materials.Bulldozers can be found on a wide range of sites,...
on private property, quarry
Quarry
A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel. They are often collocated with concrete and asphalt plants due to the requirement...
ing, agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
, fire
Fire
Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....
, development and construction of housing, roads, an oil refinery
Oil refinery
An oil refinery or petroleum refinery is an industrial process plant where crude oil is processed and refined into more useful petroleum products, such as gasoline, diesel fuel, asphalt base, heating oil, kerosene, and liquefied petroleum gas...
, and resort property, and expansion of the harbor
Harbor
A harbor or harbour , or haven, is a place where ships, boats, and barges can seek shelter from stormy weather, or else are stored for future use. Harbors can be natural or artificial...
. The plant's human-caused decline probably started with the arrival of the Polynesians
Polynesians
The Polynesian peoples is a grouping of various ethnic groups that speak Polynesian languages, a branch of the Oceanic languages within the Austronesian languages, and inhabit Polynesia. They number approximately 1,500,000 people...
. Other threats include non-native plant species
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...
, especially kaunaoa pehu (Cassytha filiformis), kiawe
Prosopis pallida
Prosopis pallida is a species of mesquite tree. It has the common names kiawe, huarango, and American carob, as well as "bayahonda" and "algarrobo blanco" . It is a thorny legume, native to Colombia, Ecuador and Peru, particularly drier areas near the coast...
(Prosopis pallida), Chinese violet
Asystasia gangetica
Asystasia gangetica is a species of plant in the Acanthaceae family. It is commonly known as the Chinese Violet, Coromandel or Creeping Foxglove. In South Africa this plant may simply be called Asystasia.-Description:...
(Asystasia gangetica), and buffel grass (Cenchrus ciliaris). Potentially damaging insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s that visit the plant include croton moth (Aechaea janata) and spiraling whitefly (Aleurodicus dispersus).
Genetic analyses
Genetic analysis
Genetic analysis can be used generally to describe methods both used in and resulting from the sciences of genetics and molecular biology, or to applications resulting from this research....
has led to recent changes in taxonomy. The rare var. kalaeloana is now called var. skottsbergii. The populations of the plant that grow on Molokai are genetically more different from var. skottsbergii than from the more common var. vaccinioides, and have been named var. audens. Furthermore, the endangered variety on Oahu is different enough that it should probably be named a new species.