''Sicyos macrophyllus'' is a rare species of flowering plant in the

Cucurbitaceae The Cucurbitaceae (), also called cucurbits or the gourd family, are a plant family (biology), family consisting of about 965 species in 101 genera.

endemic Endemism is the state of a species being found only 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 foun ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

where it is present only on the

island of Hawaii Hawaii is the List of islands of the United States by area, largest island in the United States, located in the Hawaii, state of Hawaii, the southernmost state in the union. It is the southeasternmost of the Hawaiian Islands, a chain of volcani ...

. It has likely been

extirpated Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...

from the island of

Maui Maui (; Hawaiian language, Hawaiian: ) is the second largest island in the Hawaiian archipelago, at 727.2 square miles (1,883 km2). It is the List of islands of the United States by area, 17th-largest in the United States. Maui is one of ...

.
Sicyos macrophyllus
'. NatureServe Explorer. Common names include alpine bur cucumber,
Sicyos macrophyllus
'. USDA Plants Profile. largeleaf bur-cucumber, and anunu''.
Sicyos macrophyllus
'. USFWS Species Assessment and Listing Priority Assignment Form. This is a perennial herb producing vines up to 15 meters long and 4 centimeters thick. They are supported with

tendril In botany, a tendril is a specialized Plant stem, stem, leaf or Petiole (botany), petiole with a thread-like shape used by climbing plants for support and attachment, as well as cellular invasion by parasitic plants such as ''Cuscuta''. There ar ...

s. The stems are slightly hairy and have black spots. The leaves are lobed. They are hairless on the upper surface and hairy underneath. The flowers are greenish yellow and the fruit is round. This plant can be found on the island of Hawaii at elevations between 1200 and 2000 meters. It lives in wet '' ʻōhiʻa lehua''-dominated forest and

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

forests dominated by ''

māmane ''Sophora chrysophylla'', known as ''māmane'' in Hawaiian, is a species of flowering plant in the pea and bean family, Fabaceae, that is endemic to Hawaii. It is highly polymorphic, growing as a shrub or tree, and able to reach a height of i ...

'' and ''

naio ''Myoporum sandwicense'', commonly known as ''naio'', bastard sandalwood or false sandalwood is a species of flowering plant in the figwort family, Scrophulariaceae. It is a tree or shrub highly variable in its form, the size and shape of its le ...

''. It occurs in

Hawaiʻi Volcanoes National Park Hawaii Volcanoes National Park is a national park of the United States located in Hawaii on the island of Hawaii. The park encompasses two active volcanoes: Kīlauea, one of the world's most active volcanoes, and Mauna Loa, the world's largest s ...

. There are approximately 24 to 26 individuals of this species in existence. It is not a federally listed

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

or threatened species, but the United States government made it a candidate for protection in 1990. The

United States Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is a List of federal agencies in the United States, U.S. federal government agency within the United States Department of the Interior which oversees the management of fish, wildlife, ...

considers the plant "highly threatened" and the threats are considered "imminent". However, it does not consider emergency listing necessary as of 2010.

Habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

is a main cause of the species' decline. Feral pigs, sheep, and cattle destroy native plants and cause

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

of the hilly habitat. They are also vectors for the seeds of

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

of plants, including several types of

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

. Cattle will also consume ''S. macrophyllus'' directly. Another threat to the species is competition from alien plant species. The worst offenders are fountain grass,

kikuyu grass The tropical grass species ''Cenchrus clandestinus'' (previously ''Pennisetum clandestinum'') is known by several common names, most often Kikuyu grass. It is native to the highland regions of East Africa that is home to the Kikuyu people. Becau ...

, and

German ivy ''Delairea odorata'' is a climber within the family Asteraceae that is native to South Africa. One of the two species in the genus ''Delairea'' (the other being ''Delairea aparadensis''), it was previously included in the genus ''Senecio'' as '' ...

. Alien species smother other vegetation, compete for resources, pose a fire hazard, and prevent the establishment of other species' seedlings. Some even release

allelopathic Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have ben ...

chemicals that prevent other plants from growing. The

National Park Service The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government, within the US Department of the Interior. The service manages all List ...

is attempting to prevent the

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

of this species. It has erected fences around some of the few individuals that survive today. It also tries to control invasive plants. The

National Tropical Botanical Garden The National Tropical Botanical Garden (NTBG) is a Hawaii-based not-for-profit institution dedicated to tropical plant research, conservation, and education. It operates a network of botanical gardens and preserves in Hawaii and Florida. History ...

has some seed samples.

References

{{Taxonbar, from=Q7507714 Cucurbitoideae Endemic flora of Hawaii