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.
Gouania vitifolia, also known as gray Oʻahu chewstick, is a critically endangered flowering plant in the buckthorn family, Rhamnaceae that is endemic to Hawaii. There are less than 50 known remaining plants, many of which are believed to have perished in a 2018 wildfire.
Schenkia sebaeoides, known as ʻĀwiwi in Hawaiian and lavaslope centaury in English, is a rare species of flowering plant. It is endemic to low shrublands in the state of Hawaiʻi in the United States. It is present on the islands of Kauai, Oahu, Lanai, Molokai, and Maui. At the time it was added to the endangered species list of the United States in 1991 it was known from seven populations for a total of fewer than 1000 individuals. It is threatened by habitat loss.
Euphorbia eleanoriae is a rare species of flowering plant in the euphorb family known by the common name Nā Pali sandmat. It is endemic to Kauaʻi, Hawaii. Like other native Hawaiian euphorbs it is called ʻakoko locally. This plant was only discovered in 1992 and described to science in 1996 as Chamaesyce eleanoriae. At that time there were fewer than 500 plants known, all occurring in small populations scattered across the sheer cliffs along the Nā Pali Coast of Kauaʻi. By 2001 the total population had already dropped; only three populations were found, for a total of fewer than 50 plants. The plant was federally listed as an endangered species of the United States in 2010.
Cyanea longiflora is a rare species of flowering plant in the bellflower family known by the common name ridge rollandia. It is endemic to Oahu where there are only three remaining occurrences in the northern Waianae Mountains for a total of under 300 individuals. It is a federally listed endangered species. Like other Cyanea it is known as haha in Hawaiian.
Cyperus trachysanthos is a rare species of sedge known by the common names pu`uka`a and sticky flatsedge. It is endemic to Hawaii, where it is known from Kauai and Oahu. It was known from Niihau, Molokai and Lanai, but it has been extirpated from these islands. It is a federally listed endangered species of the United States.
Delissea rhytidosperma, is known by the common names Kauai delissea, Kauai leechleaf delissea, and leechleaf delissea. It is a rare species of flowering plant in the bellflower family, that is endemic to Hawaii where it is known only from the island of Kauai. It is critically endangered or extinct in the wild.
Delissea subcordata is a rare species of flowering plant in the family Campanulaceae known by the common names Koʻolau Range delissea and oha. It is endemic to Hawaii, where it is known only from the island of Oahu. It is now only found in the Waianae Mountains, and it is believed to be extirpated from the Koʻolau Range, where it once occurred. As of 2008 there were 40 individuals remaining, 28 of which were mature plants. This plant was federally listed as an endangered species of the United States in 1996.
Dubautia latifolia is a rare species of flowering plant in the family Asteraceae known by the common name koholapehu. It is endemic to Hawaii where it is known only from the west side of the island of Kauai. 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.
Isodendrion laurifolium is a rare species of flowering plant in the violet family known by the common names rockcliff isodendrion and aupaka. It is endemic to Hawaii, where it is known from fewer than 1000 individuals on the islands of Kauai and Oahu. It is a federally listed endangered species of the United States.
Isodendrion longifolium is a rare species of flowering plant in the violet family known by the common names longleaf isodendrion and aupaka. It is endemic to Hawaii, where it is known from fewer than 1000 individuals on the islands of Kauai and Oahu. It is a federally listed threatened species of the United States.
Lysimachia filifolia is a rare species of flowering plant in the Primulaceae known by the common name Wailua River yellow loosestrife. It is endemic to Hawaii, where there are two populations on Oahu and one on 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.
Nototrichium humile is a rare species of flowering plant in the family Amaranthaceae known by the common names kaala rockwort and kulu'i. It is endemic to Hawaii, where it is now limited to the island of Oahu, having been extirpated from Maui. It is a federally listed endangered species of the United States.
Peucedanum sandwicense is a rare species of flowering plant in the carrot family known by the common name makou. It is endemic to Hawaii, where it is known from Maui, Molokai, Kauai, and Oahu. It is threatened by introduced species of plants and animals. It is a federally listed threatened 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.
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.
Schiedea hookeri is a rare species of flowering plant in the family Caryophyllaceae known by the common names Hooker's schiedea and sprawling schiedea. It is endemic to Hawaii, where it is known only from the island of Oahu. It is thought to have been extirpated from Haleakalā on Maui. It is threatened by the degradation and destruction of its habitat. It was federally listed as an endangered species of the United States in 1996.
Solanum sandwicense is a rare species of flowering plant in the nightshade family known by the common names Hawai'i horsenettle and popolo 'aiakeakua. It is endemic to Hawaii, where it occurs today on the islands of Kauai and Oahu. It is threatened by the destruction and degradation of its habitat. It is a federally listed endangered species of the United States.
