The Hawaiian tropical rainforests are a tropical moist broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of 6,700 km2 (2,600 sq mi) in the windward lowlands and montane regions of the islands. Coastal mesic forests are found at elevations from sea level to 300 m (980 ft). Mixed mesic forests occur at elevations of 750 to 1,250 m, while wet forests are found from 1,250 to 1,700 m. Moist bogs and shrublands exist on montane plateaus and depressions. For the 28 million years of existence of the Hawaiian Islands, they have been isolated from the rest of the world by vast stretches of the Pacific Ocean, and this isolation has resulted in the evolution of an incredible diversity of endemic species, including fungi, mosses, snails, birds, and other wildlife. In the lush, moist forests high in the mountains, trees are draped with vines, orchids, ferns, and mosses. This ecoregion includes one of the world's wettest places, the slopes of Mount Waiʻaleʻale, which average 373 in (9,500 mm) of rainfall per year.
The ʻanianiau is a species of Hawaiian honeycreeper that is endemic to upper elevation forests on the island of Kauai.
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.
Dubautia herbstobatae, the Na'ena'e or Keaau Valley dubautia, is an endangered species of shrub which is endemic to Oahu, Hawaii.
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.
Dubautia imbricata is a rare species of flowering plant in the family Asteraceae known by the common names bog dubautia and imbricate dubautia. It is endemic to Hawaii where it is known only from the island of Kauai. There are four known occurrences. Like other Dubautia this plant is known as na`ena`e.
Dubautia kalalauensis is a rare species of flowering plant in the family Asteraceae. It is endemic to Hawaii where it is known only from the island of Kauai. There is only a single known population composed of 26 plants. It was federally listed as an endangered species of the United States in 2010. Like other Dubautia this plant is known as na`ena`e.
Dubautia kenwoodii, the Kalalau rim dubautia, is an "extremely rare" species of flowering plant in the family Asteraceae. It is endemic to Hawaii where it is known only from the island of Kauai. Only one plant has ever been seen: the type specimen. A part of this plant was collected in 1991 and the individual was described as a new species in 1998. It was federally listed as an endangered species of the United States in 2010. Like other Dubautia this plant is known as na`ena`e.
Dubautia pauciflorula is a rare species of flowering plant in the family Asteraceae known by the common name Wahiawa Bog dubautia. It is endemic to Hawaii where it is known only from the Wahiawa Mountains on the island of Kauai.
Dubautia plantaginea is a rare species of flowering plant in the aster family known by the common name plantainleaf dubautia. It is endemic to Hawaii where it is the only member of the silversword alliance that is found on all six of the largest islands. Two of the three subspecies are rare and endangered. Like other Dubautia this plant is called na`ena`e.
Dubautia waialealae is a rare species of flowering plant in the family Asteraceae known by the common name Wai'ale'ale dubautia. Like other Dubautia this plant is called na`ena`e.
Exocarpos luteolus is a rare species of flowering plant in the sandalwood family known by the common names leafy ballart or heau. It is endemic to Hawaii, where it is known only from the island of Kauai. There are eight populations remaining, for a total global population of only 39 individuals. The plant was federally listed as an endangered species of the United States in 1994.
Gouania meyenii is a rare species of flowering plant known by the common name smoothfruit chewstick. It is endemic to Hawaii, where it is known only from Oahu and Kauai. It is estimated that there are between 38 and 63 individuals of this species remaining in the wild. It is a federally listed endangered species of the United States.
Kadua st-johnii is a rare species of flowering plant in the coffee family known by the common name Nā Pali beach starviolet. It is endemic to Hawaii, where it is known only from the Nā Pali coast of Kauai. It is a federally listed endangered species of the United States.
Cyperus pennatiformis is a rare species of sedge known by the common name coastal flatsedge. It is endemic to Hawaii, where it grows on the islands of Maui, Kauai, and Laysan. It is a federally listed endangered species of the United States.
Peristylus holochila is a rare species of orchid known by the common name Hawaii bog orchid. It is endemic to Hawaii. It is a federally listed endangered species of the United States.
Poa mannii is a rare species of grass known by the common names Mann's bluegrass and Olokele Gulch bluegrass. It is endemic to Hawaii, where it is limited to the island of Kauai. It is threatened by the loss and modification of its habitat. It is a federally listed endangered species of the United States.
Remya kauaiensis is a rare species of flowering plant in the family Asteraceae, known by the common name of Kauai remya. It is endemic to Hawaii, where it is known only from the island of Kauai. It is threatened by the degradation of its habitat. It is a federally listed endangered species of the United States.
Remya montgomeryi is a rare species of flowering plant in the family Asteraceae known by the common name Kalalau Valley remya. It is endemic to Hawaii, where it is known only from the island of Kauai. It is threatened by the degradation of its habitat. It is a federally listed endangered species of the United States.
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.
