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.
Hibiscadelphus distans is an extremely rare species of flowering plant in the mallow family, Malvaceae, that is endemic to the island of Kauaʻi in Hawaii. It is known as hau kuahiwi in Hawaiian, which means "upland Hibiscus tiliaceus." It is a bush or small tree with heart-shaped leaves and yellow flowers and grows at between 1,000 and 1,800 feet in the remnants of native dry forests. Despite its rarity, it is believed to be the only surviving species in the genus Hibiscadelphus which is only known from Hawaii, the other five species having recently become extinct in the wild, some being known from only a single plant.
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, such as zoos, 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.
Kokia kauaiensis, the Kauai treecotton or Kauaʻi Kokiʻo, is a species of flowering plant in the mallow family, Malvaceae, that is endemic to Kauaʻi, Hawaii.
The Mauna Loa silversword, Argyroxiphium kauense, or Kaʻū silversword, is a rare species of flowering plant in the aster family. It is endemic to the eastern and southern slopes of Mauna Loa on the island of Hawaiʻi. A. kauense occurs in mountainous shrublands, bogs, and open mesic forest. The species is managed by the National Park Service and Hawaiʻi State Department of Forestry and Wildlife. It is a federally listed endangered species of the United States. There are three known populations remaining, for a total of fewer than 1000 individuals.
Schiedea adamantis, commonly known as Diamond Head schiedea, is a species of flowering plant in the family Caryophyllaceae, that is endemic to the island of Oʻahu in Hawaii. It inhabits low shrublands on steep slopes along the northwest rim of Diamond Head Crater. Associated plants include nehe, kā
Lipochaeta, common name nehe, is a genus of flowering plants in the family Asteraceae that is endemic to Hawaii.
Melanthera, is a genus of perennial flowering plants in the family Asteraceae, native to the tropical and subtropical Americas.
Cyanea crispa is a rare species of flowering plant known by the common names crimped rollandia and Koolau Range rollandia. It is endemic to Oahu, where there are no more than fifty individuals remaining in the Koʻolau Range. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
Cyanea acuminata is a rare species of flowering plant known by the common names Honolulu cyanea. It is endemic to Oahu, where there are no more than 250 individuals remaining. It is a federally listed endangered species of the United States. Like other Cyanea it is known as haha in Hawaiian.
Cyanea hamatiflora is a rare species of flowering plant in the bellflower family known by the common name wetforest cyanea. It is endemic to Hawaii, where it is known from the islands of Maui and Hawaii, and there are probably fewer than 250 plants remaining in total. It is a federally listed endangered species. 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.
Isodendrion hosakae is a rare species of flowering plant in the violet family known by the common names cindercone isodendrion and aupaka. It is endemic to Hawaii, where it is known from fewer than 1000 individuals on the island of Hawaii. It is a federally listed endangered species of the United States.
Lipochaeta fauriei known by the common name Olokele Canyon nehe, is a rare species of flowering plant in the aster family.
Lipochaeta kamolensis known by the common name Maui nehe, is a rare species of flowering plant in the family Asteraceae.
Lipochaeta micrantha, known by the common name Kauai nehe, is a rare species of flowering plant in the family Asteraceae.
Lipochaeta tenuifolia is a rare species of flowering plant in the family Asteraceae known by the common names Waianae Range nehe and slender-leaf nehe.
Lipochaeta waimeaensis is a rare species of flowering plant in the family Asteraceae known by the common name Waimea Canyon nehe. It is endemic to Hawaii, where it is known only from the island of Kauai. It is federally listed as an endangered species of the United States.
Lysimachia venosa is a rare species of flowering plant in the family Primulaceae known by the common name veined yellow loosestrife. It is endemic to Hawaii, where it is known only from the island of Kauai. The plant was only collected twice, last in 1911, but in 1991, a branch was discovered that had broken off the steep cliffs above the headwaters of the Wailua River. The branch was from a plant of this species and may have fallen from the summit of Mount Waialeale. No more specimens have been found since and the plant may be extinct, but some experts believe it may still exist in unsurveyed parts of the habitat. It was federally listed as an endangered species of the United States in 2010.
Schiedea attenuata is a rare species of flowering plant in the family Caryophyllaceae known by the common name Kalalau schiedea. It is endemic to Hawaii, where it is known only from the Kalalau Valley on the island of Kauai. It is threatened by the degradation of its habitat. It was federally listed as an endangered species of the United States in 2010.
