''Acacia koaia'', known as ''koaia'' or ''koaie'' in Hawaiian, is a species of

acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...

that is endemic to Hawaii. It is closely related to ''koa'' (''

Acacia koa ''Acacia koa'' or commonly known as koa is a species of flowering tree in the family Fabaceae. It is endemic to the Hawaiian Islands, where it is the second most common tree. The highest populations are on Hawaii, Maui and Oahu. Name The name ...

''), and is sometimes considered to be the same species.

Description

''Acacia koaia'' is usually distinguished by growing as a short (rarely more than ), broad, gnarled tree; having the

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s longitudinally arranged in the pod; shorter, straighter

phyllode Phyllodes are modified petioles or leaf stems, which are leaf-like in appearance and function. In some plants, these become flattened and widened, while the leaf itself becomes reduced or vanishes altogether. Thus the phyllode comes to serve the ...

s; and much denser wood. A population on the northern coast 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 ...

may be intermediate, but the relationships have not been worked out. ''Koaia'' wood is claimed to be very different from that of ''koa'', and this may be the best character to separate them.

Distribution

''Acacia koaia'', ''Koaia'', is highly adapted to dry habitats, and is capable of forming dense forests in areas with very little rainfall. It was formerly found widely in

dry forests The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...

on all of the main islands. Associated plants include ''uluhe'' (''

Dicranopteris ''Dicranopteris'' (forkedfern) is a genus of tropical ferns of the family Gleicheniaceae. There are about 20 described species. Species , ''Plants of the World Online Plants of the World Online (POWO) is an online database published by the R ...

linearis''), ''hala'' (''

Pandanus tectorius ''Pandanus tectorius'' is a species of ''Pandanus'' (screwpine) that is native to Malesia, Papuasia, eastern Australia, and the Pacific Islands. It grows in the coastal lowlands typically near the edge of the ocean. Common names in English inclu ...

''), ''kookoolau'' (''

Bidens ''Bidens'' is a genus of flowering plants in the aster family, Asteraceae.''Bidens''.
Flo ...

'' spp.), ''kokio'' (''

Hibiscus kokio Hawaiian hibiscus are seven species of hibiscus native to Hawaii. The yellow hibiscus is Hawaii's state flower. Most commonly grown as ornamental plants in the Hawaiian Islands are the non-native Chinese hibiscus (''Hibiscus rosa-sinensis'') and it ...

''), ''nehe'' (''

Lipochaeta ''Lipochaeta'', common name nehe, is a genus of flowering plants in the family Asteraceae that is endemic to Hawaii. Taxonomy There are difficulties regarding the classification of this genus for its affinities are uncertain. Some studies have ...

'' spp.), ''hala pepe'' ('' Dracaena'' spp.), and ''ōhia lehua'' (''

Metrosideros polymorpha ''Metrosideros polymorpha'', the ''ōhia lehua'', is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations, ...

''). Like many legumes, ''koaia'' is able to fix nitrogen. However, it has been devastated by

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 other

ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, cam ...

s and is now rare. It can be seen on ranch land in

North Kohala image:HawaiiIslandDistrict-NorthKohala.svg, The districts of the Hawaii (island), Big Island. From Northernmost, clockwise; North Kohala (highlighted), Hāmākua, North Hilo, Hawaii, Hilo, South Hilo, Hawaii, Hilo, Puna, Hawaii, Puna, Kau, Hawaii, ...

, and at a small fenced exclosure outside of Waimea known as the ''koaia'' sanctuary. ''Koaia'' is one of the species being used to revegetate the island of

Kahoolawe Kahoolawe (Hawaiian: ), anglicized as Kahoolawe (), is the smallest of the eight main volcanic islands in the Hawaiian Islands. Kahoolawe is located about southwest of Maui and also southeast of Lānaʻi, and it is long by wide, with a total ...

, which lost most of its plant life to

overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...

and ordnance testing.

Uses

Medicinal

Native Hawaiians Native Hawaiians (also known as Indigenous Hawaiians, Kānaka Maoli, Aboriginal Hawaiians, First Hawaiians, or simply Hawaiians) ( haw, kānaka, , , and ), are the indigenous ethnic group of Polynesian people of the Hawaiian Islands. Hawaii ...

ground ''koaia'' leaves and bark with ''auaukoi'' (''

Senna occidentalis ''Senna occidentalis'' ndian vernacular name ''Usaya ki Fali''is a pantropical plant species, native to the Americas. The species was formerly placed in the genus '' Cassia''. Vernacular names in English include septicweed, coffee senna, coffee ...

'') and ''kikānia pipili'' (''

Desmodium ''Desmodium'' is a genus of plants in the legume family Fabaceae, sometimes called tick-trefoil, tick clover, hitch hikers or beggar lice. There are dozens of species and the delimitation of the genus has shifted much over time. These are mostly ...

sandwicense'') stalks. The mixture was then hydrated and used in a

steam bath A steam bath is a steam-filled room for the purpose of relaxation and cleansing. It has a long history, going back to Greek and Roman times. History The origins of the steam bath come from the Roman bath, which began during the height of the R ...

to treat diseased skin.

Non-medicinal

The wood of ''koaia'' is harder and more dense than that of '' koa''. It was used to make ''laau melomelo'' (

fishing lure A fishing lure is a broad type of artificial angling baits that are replicas designed to mimic real prey animals and attract the attention of predatory fish, using appearances, flashy colors, bright reflections, movements, vibrations and/or lou ...

s), ''hoe'' (

paddle A paddle is a handheld tool with an elongated handle and a flat, widened distal end (i.e. the ''blade''), used as a lever to apply force onto the bladed end. It most commonly describes a completely handheld tool used to propel a human-powered wa ...

s), ''ihe'' (short

spear A spear is a pole weapon consisting of a shaft, usually of wood, with a pointed head. The head may be simply the sharpened end of the shaft itself, as is the case with fire hardened spears, or it may be made of a more durable material fasten ...

s), ''pololu'' (long spears), ''ōō'' (

digging stick A digging stick, sometimes called a yam stick, is a wooden implement used primarily by subsistence-based cultures to dig out underground food such as roots and tubers, tilling the soil, or burrowing animals and anthills. It is a term used in ar ...

s), ''ie kūkū'' (square ''

kapa Kapa is a fabric made by native Hawaiians from the bast fibres of certain species of trees and shrubs in the orders Rosales and Malvales. Description and uses It is similar to ''tapa'' found elsewhere in Polynesia (the Hawaiian phoneme corre ...

'' beaters), and ''papa olonā'' ('' Touchardia latifolia'' scrapers). ''Koaia'' leaves were used to cover ''hale lau koaie'' (shelters and permanent sheds).

Gallery

Image:Starr_020124-0067_Acacia_koaia.jpg Image:Starr_020124-0065_Acacia_koaia.jpg Image:Acacia_koaia3.jpg, Image:Starr_030523-0040_Acacia_koaia.jpg Image:Starr_020124-0063_Acacia_koaia.jpg Image:Starr_060922-9175_Acacia_koaia.jpg Image:Starr_010516-0034_Acacia_koaia.jpg Image:Acacia koaia wood.jpg Image:Acacia_koaia1.jpg, Image:Kohala_pasture.jpg,

References

External links

Photos of ''Acacia koaia''
at Hawaiian Ecosystems at Risk Project (HEAR) {{Taxonbar, from=Q2074762 koaia Endemic flora of Hawaii Trees of Hawaii Plants described in 1888