''Schenkia sebaeoides'', known as Āwiwi in Hawaiian and lavaslope centaury in

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

, is a rare species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

. 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 ...

to low shrublands in the state of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. It is present on the islands of

Kauai Kauai, () anglicized as Kauai ( ), is geologically the second-oldest of the main Hawaiian Islands (after Niʻihau). With an area of 562.3 square miles (1,456.4 km2), it is the fourth-largest of these islands and the 21st largest island ...

Oahu Oahu () (Hawaiian language, Hawaiian: ''Oʻahu'' ()), also known as "The Gathering place#Island of Oʻahu as The Gathering Place, Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over t ...

, Lanai,

Molokai Molokai , or Molokai (), is the fifth most populated of the eight major islands that make up the Hawaiian Islands, Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its greatest length an ...

, and Maui. At the time it was added to the

endangered species list On 29 January 2010, the IUCN Red List of Threatened Species identified 5220 (2754 animals, 1 fungus, 2464 plant, 1 protist) endangered species, subspecies and varieties, stocks and sub-populations. For IUCN lists of endangered species by kingd ...

of the United States in 1991 it was known from seven populations for a total of fewer than 1000 individuals.USFWS
''Centaurium sebaeoides'' Five Year Review.
August 27, 2010. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. Until 2004 it was a member of genus ''

Centaurium ''Centaurium'' (centaury) is a genus of 20 species in the gentian family (Gentianaceae), tribe Chironieae, subtribe Chironiinae. The genus was named after the centaur Chiron, famed in Greek mythology for his skill in medicinal herbs. It is dist ...

''; it and several other species have since been transferred to other genera. This is the only plant in the

gentian ''Gentiana'' is a genus of flowering plants belonging to the gentian family (Gentianaceae), the tribe Gentianeae, and the monophyletic subtribe Gentianinae. With about 400 species it is considered a large genus. They are notable for their mostl ...

family,

Gentianaceae Gentianaceae is a family of flowering plants of 103 genera and about 1600 species. Etymology The family takes its name from the genus '' Gentiana'', named after the Illyrian king Gentius. Distribution Distribution is cosmopolitan. Characteri ...

, that is native to Hawaii. This is an annual herb, one of only 3% of Hawaiian flora that have annual life cycles. It often bears white flowers but pink flowers are not uncommon. The number and size of populations fluctuates quite a bit, and there may be unknown small, ephemeral populations that exist for a season and then die away. The species likely has a large

soil seed bank The soil seed bank is the natural storage of seeds, often dormant, within the soil of most ecosystems. The study of soil seed banks started in 1859 when Charles Darwin observed the emergence of seedlings using soil samples from the bottom of a lak ...

and when an area gets higher

rainfall Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

there is a greater

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...

rate. The plant is somewhat nondescript and resembles two species of common weeds,

scarlet pimpernel ''The Scarlet Pimpernel'' is the first novel in a series of historical fiction by Baroness Orczy, published in 1905. It was written after her stage play of the same title (co-authored with Montague Barstow) enjoyed a long run in London, having ...

(''Anagallis arvensis'') and bitter herb (''Centaurium erythraea''), so it may grow unnoticed in some areas. Surveys occur every few years and find varying numbers of populations. 2010 estimates list three populations on Kauai with up to 52 plants total, four populations on Molokai with several thousand plants, two populations on Oahu with up to 130 plants, seven or eight populations on Maui with several thousand individuals, and only a few plants on Lanai in a single population. The global population is estimated at about 6000 during wet years. This plant occurs in sand and volcanic and clay soils on bluffs and

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

s in drier coastal areas. A major threat to the species is the

invasion An invasion is a Offensive (military), military offensive in which large numbers of combatants of one geopolitics, geopolitical Legal entity, entity aggressively enter territory (country subdivision), territory owned by another such entity, gen ...

of introduced plant species such as ''

Casuarina equisetifolia ''Casuarina equisetifolia'', common names ''Coastal She-oak'' or ''Horsetail She-oak'' (sometimes referred to as the Australian pine tree or whistling pine tree outside Australia), is a she-oak species of the genus ''Casuarina''. The native ...

'', '' C. glauca'', ''

Prosopis pallida ''Prosopis pallida'' is a species of mesquite tree. It has the common names kiawe () (in Hawaii), huarango (in its native South America) and American carob, as well as "bayahonda" (a generic term for ''Prosopis''), "algarrobo pálido" (in some pa ...

'', and ''

Bryophyllum pinnatum ''Kalanchoe pinnata'', commonly known as cathedral bells, air plant, life plant, miracle leaf, and Goethe plant is a succulent plant native to Madagascar. It is a popular houseplant and has become naturalized in tropical and subtropical areas. T ...

''. Each island has a different array of invasive flora, so management plans vary. ''Casuarina'' species are among the worst offenders because they spread so thickly they outcompete smaller plants. Many parts of its habitat are degraded by

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals ...

including

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

and

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s, which trample and compact the soil, and by

off-road vehicle An off-road vehicle, sometimes referred to as an overland or adventure vehicle, is considered to be any type of vehicle which is capable of driving on and off paved or gravel surface. It is generally characterized by having large tires with de ...

s. This damage can lead to

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

. Plants occurring near trails may be trampled by

hikers Hiking is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century.AMATO, JOSEPH A. "Mind over Foot: Romantic Walking and Rambling." In ''On Foot: A Hist ...

. Fire is a threat to some populations.

References

External links

* * {{Taxonbar, from=Q279618 sebaeoides Endemic flora of Hawaii Plants described in 1853 Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN