Located about 2,300 miles (3,680 km) from the nearest continental shore, the Hawaiian Islands are the most isolated group of islands on the planet. The plant and animal life of the Hawaiian archipelago is the result of early, very infrequent colonizations of arriving species and the slow evolution of those species—in isolation from the rest of the world's flora and fauna—over a period of at least 5 million years. As a consequence, Hawai'i is home to a large number of endemic species. The radiation of species described by Charles Darwin in the Galapagos Islands which was critical to the formulation of his theory of evolution is far exceeded in the more isolated Hawaiian Islands.
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 and its numerous hybrids, though the native Hibiscus arnottianus is occasionally planted.
The Hawaiian lobelioids are a group of flowering plants in the bellflower family, Campanulaceae, subfamily Lobelioideae, all of which are endemic to the Hawaiian Islands. This is the largest plant radiation in the Hawaiian Islands, and indeed the largest on any island archipelago, with over 125 species. The six genera involved can be broadly separated based on growth habit: Clermontia are typically branched shrubs or small trees, up to 7 metres (23 ft) tall, with fleshy fruits; Cyanea and Delissea are typically unbranched or branching only at the base, with a cluster of relatively broad leaves at the apex and fleshy fruits; Lobelia and Trematolobelia have long thin leaves down a single, non-woody stem and capsular fruits with wind-dispersed seeds; and the peculiar Brighamia have a short, thick stem with a dense cluster of broad leaves, elongate white flowers, and capsular fruits. The relationships among the genera and sections remains unsettled as of April 2022.
A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as only consisting of living members kept in captivity or as a naturalized population outside its historic range. Classification requires exhaustive surveys conducted within the species' known habitat with consideration given to seasonality, time of day, and life cycle. Once a species is classified as EW, the only way for it to be downgraded is through reintroduction.
The Hawaiʻi mamo is an extinct species of Hawaiian honeycreeper. It was endemic to Hawaii Island. It became extinct due to habitat loss, mosquitoes, introduced predators such as the small Indian mongoose, and overcollecting.
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, invasive species, and climate change. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration.
Colubrina oppositifolia, known as kauila in Hawaiian, is a rare species of flowering tree in the family Rhamnaceae endemic to Hawaii.
Argyroxiphium sandwicense subsp. sandwicense, the Mauna Kea silversword, is a highly endangered flowering plant endemic to the island of Hawaiʻi of Hawaii. It is the "crown jewel" of the volcanic mountain Mauna Kea, from which it derives its English name. The Hawaiian name is ʻahinahina; it applies to silverswords more broadly. The Mauna Kea silversword was once common on the volcano, and extraordinary conservation efforts are being made to preserve the species.
Clermontia drepanomorpha is a rare species of flowering plant in the bellflower family known by the common name Kohala Mountain clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as `oha wai. This plant is endemic to Kohala, a volcano at the northern end of the island of Hawaii. This is a federally listed endangered species of the United States. It is a perennial tree that can be terrestrial or epiphytic and it grows in wet boggy forests.
Clermontia lindseyana is a rare species of flowering plant in the bellflower family known by the common name hillside clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as `oha wai. This plant is known only from Haleakalā, a volcano on the island of Maui, and Mauna Loa and Mauna Kea, volcanoes on the island of Hawaii. This is a federally listed endangered species of the United States.
Clermontia oblongifolia is a species of flowering plant in the bellflower family known by the common name Oahu clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as ʻoha wai. This plant is native to three of the Hawaiian Islands, where one subspecies is not uncommon but the other two are very rare and endangered.
Clermontia pyrularia is a rare species of flowering plant in the bellflower family known by the common names Hamakua clermontia and pear clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as ʻoha wai and haha. It is endemic to the island of Hawaiʻi, where there is one remaining wild population containing 15 individuals and several propagated individuals that have been planted in protected habitat. This is a federally listed endangered species of the United States.
Clermontia samuelii is a rare species of flowering plant in the bellflower family known by the common name Hana clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as `oha wai. This plant is endemic to Maui, where there are fewer than 250 mature specimens remaining. This is a federally listed endangered species of the United States.
Cyanea copelandii is a rare species of flowering plant in the bellflower family known by the common name treetrunk cyanea. It is endemic to Maui, where there are no more than 250 individuals remaining in the wild. It is a federally listed endangered species of the United States. Like other Cyanea it is known as hāhā in Hawaiian.
Cyanea glabra is a rare species of flowering plant in the family Campanulaceae known by the common name smooth cyanea. It is endemic to Maui, where there are twelve plants remaining in the wild. It was federally listed as an endangered species of the United States with nine other Maui Nui endemics in 1999. Like other Cyanea it is known as haha in Hawaiian.
Cyanea grimesiana is a rare species of flowering plant in the bellflower family known by the common name splitleaf cyanea. It is native to Oahu and Molokai, where it is known from 12 occurrences. It is a federally listed endangered species. Like other Cyanea it is known as haha in Hawaiian.
Cyanea procera is a rare species of flowering plant in the bellflower family known by the common name Molokai cyanea. It is endemic to Hawaii, where it is known only from the island of Molokaʻi. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
Cyanea superba is a rare species of flowering plant in the bellflower family known by the common names Mt. Kaala cyanea and superb cyanea. It is endemic to the island of Oahu, but it is now extinct in the wild. It exists in cultivation and some individuals have been planted in appropriate habitat. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
Cyanea truncata is a rare species of flowering plant in the bellflower family known by the common name Punaluu cyanea. It is endemic to the islands of Oahu and Molokai in Hawaii, but it is now critically endangered. It exists in cultivation and some individuals have been planted in appropriate habitat. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
