Sesbania tomentosa
Encyclopedia
Sesbania tomentosa, commonly known as Ōhai, is an endangered species of flowering plant
in the pea
family
, Fabaceae
, that is endemic to the main Hawaiian Islands
as well as Nihoa
and Necker Island. It inhabits low shrublands
and, rarely, dry forests
, at elevations from sea level to 2500 ft (762 m). Associated native plant species include akiaki (Sporobolus virginicus
), ilima (Sida fallax
), naupaka kahakai (Scaevola
taccada
), and pili (Heteropogon contortus
). Off-road vehicles, wildfire
s, grazing, and alien species competition have destroyed their habitat on the main islands, but they are still quite common on Nihoa and Necker. At least 2000 specimens grow on Nihoa, while there are far less on Necker.
Ōhai is highly polymorphic
, exhibiting broad variations in color and shape. Plants that grow on Nihoa have reddish-orange flowers and young leaflets that are relatively hairless. Necker plants have salmon to orange colored-flowers, and leaflets that are very hairy. A form that grows as a standing tree exists on Molokai
.
Ōhai grows as a prostrate shrub with semi-glaucous leaves devoid of tomentum on the southernmost tip of the island of Hawaii
, Ka Lae
.
|first=Rick |last=Barboza |volume=10 |issue=273 |date=2005-09-03}}
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the pea
Pea
A pea is most commonly the small spherical seed or the seed-pod of the pod fruit Pisum sativum. Each pod contains several peas. Peapods are botanically a fruit, since they contain seeds developed from the ovary of a flower. However, peas are considered to be a vegetable in cooking...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Fabaceae
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
, that is endemic to the main Hawaiian Islands
Hawaiian Islands
The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...
as well as Nihoa
Nihoa
Nihoa , also known as Bird Island or Moku Manu, is the largest and tallest of ten islands and atolls in the uninhabited Northwestern Hawaiian Islands . The island is located at the southern end of the NWHI chain, southeast of Necker Island...
and Necker Island. It inhabits low 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...
and, rarely, dry forests
Hawaiian tropical dry forests
The Hawaiian tropical dry forests are a tropical dry broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of on the leeward side of the main islands and the summits of Niihau and Kahoolawe. These forests are either seasonal or sclerophyllous. Annual rainfall is less than and...
, at elevations from sea level to 2500 ft (762 m). Associated native plant species include akiaki (Sporobolus virginicus
Sporobolus virginicus
Sporobolus virginicus, known by numerous common names including Marine Couch, Sand Couch, Coastal Rat-tail Grass, Salt Couch Grass, Saltwater Couch and Nioaka, is a coastal non-bunching tussock grass with a wide distribution.-Description:It is a perennial tussock grass from 10 to 50 centimetres in...
), ilima (Sida fallax
Sida fallax
Sida fallax, known as ilima in Hawaiian, is a species of herbaceous flowering plant in the Hibiscus family, Malvaceae, that occurs on most of the Pacific Islands. The flowers are small, in diameter, have five petals, and are a golden yellow in color. Plants may be erect or prostrate and are found...
), naupaka kahakai (Scaevola
Scaevola
Scaevola is a genus of flowering plants in the Goodenia family, Goodeniaceae. It consists of more than 130 tropical species, with the center of diversity being Australia and Polynesia, including Hawaii....
taccada
Scaevola taccada
Scaevola taccada, also known as Beach Cabbage, Sea Lettuce, Beach Naupaka, Naupaka kahakai , Merambong and Ngahu is a flowering plant in the family Goodeniaceae found in open coastal locations of the tropical areas of the Indo-Pacific...
), and pili (Heteropogon contortus
Heteropogon contortus
Heteropogon contortus is a tropical, perennial tussock grass with a native distribution encompassing Southern Africa, southern Asia, Northern Australia and Oceania. The species has also become a naturalised weed in tropical and subtropical regions in the Americas and East Asia. The plant grows to ...
). Off-road vehicles, 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...
s, grazing, and alien species competition have destroyed their habitat on the main islands, but they are still quite common on Nihoa and Necker. At least 2000 specimens grow on Nihoa, while there are far less on Necker.
Ōhai is highly polymorphic
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
, exhibiting broad variations in color and shape. Plants that grow on Nihoa have reddish-orange flowers and young leaflets that are relatively hairless. Necker plants have salmon to orange colored-flowers, and leaflets that are very hairy. A form that grows as a standing tree exists on 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...
.
Ōhai grows as a prostrate shrub with semi-glaucous leaves devoid of tomentum on the southernmost tip of the island of Hawaii
Hawaii (island)
The Island of Hawaii, also called the Big Island or Hawaii Island , is a volcanic island in the North Pacific Ocean...
, Ka Lae
Ka Lae
Ka Lae , also known as South Point, is the southernmost point of the Big Island of Hawaii and of the 50 United States. The Ka Lae area is registered as a National Historic Landmark District under the name South Point Complex...
.
External links
i at Mānoa]] |accessdate=}}Ohai leaf tips give off sweet scent |work=Honolulu Star-BulletinHonolulu Star-Bulletin
The Honolulu Star-Bulletin was a daily newspaper based in Honolulu, Hawaii, United States. At the time publication ceased on June 6, 2010, it was the second largest daily newspaper in the state of Hawaii...
|first=Rick |last=Barboza |volume=10 |issue=273 |date=2005-09-03}}