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.
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.
Eragrostis fosbergii is a rare species of grass known by the common name Fosberg's love grass. It is endemic to Hawaii, where it is known only from the Waianae Mountains on the island of Oahu. It was federally listed as an endangered species in 1996.
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.
Haplostachys haplostachya is a rare species of flowering plant in the mint family known by the common names honohono or Hawaiian mint. It is endemic to Hawaii, where it is now limited to the island of Hawaii and has been extirpated from Kauai and Maui. It has been on the United States' endangered species list since 1979.
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 iniki is a rare species of flowering plant in the family Primulaceae known by the common names Wailua River yellow loosestrife and Wailua River island-loosestrife. It is endemic to Hawaii, where there is only one known occurrence existing on the island of Kauai. The plant was federally listed as an endangered species of the United States in 2010.
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.
Neraudia angulata is a rare species of flowering plant in the nettle family known by the common name angularfruit ma'oloa. It is endemic to Hawaii, where it is known only from the Waianae Range on the island of Oahu. There are nine remaining populations with a varying number of individuals; in 2006 there were 227 mature individuals counted. This is a federally listed endangered species of the United States.
Phyllostegia hirsuta is a species of flowering plant in the mint family known by the common names Molokai phyllostegia and hairy phyllostegia. It is endemic to Hawaii, where it is known only from the island of Oahu. It is a federally listed endangered species of the United States.
Sanicula mariversa is a rare species of flowering plant in the family Apiaceae known by the common name Waianae Range black-snakeroot. It is endemic to Hawaii, where it is known only from the Waianae Mountains on the island of Oahu. It is threatened by the degradation of its habitat. It is a federally listed endangered species of the United States.
Sanicula purpurea is a rare species of flowering plant in the carrot family known by the common names purple-flower black-snakeroot and purple-flowered sanicle. It is endemic to Hawaii, where it is known from Maui and from the Koolau Mountains on the island of Oahu. It is threatened by the degradation of its habitat. It was federally listed as endangered species of the United States in 1996.
Schiedea kealiae is a rare species of flowering plant in the family Caryophyllaceae known by the common name Waianae Range schiedea. It is endemic to Hawaii, where it is known only from the Waianae Range on the island of Oahu. 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.
Schiedea membranacea is a rare species of flowering plant in the family Caryophyllaceae known by the common name valley schiedea. It is endemic to Hawaii, where it is known only from the island of Oahu. It has been extirpated from Maui and Molokai. Plants in a population known from Kauai are actually members of other species. Thus, the species is now endemic to Oahu. It is threatened by the degradation and destruction of its habitat. It is a federally listed endangered species of the United States.
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.
Stenogyne bifida is a rare species of flowering plant in the mint family known by the common name twocleft stenogyne. It is endemic to Hawaii, where it is known only from the island of Molokai. As of 2010 there was only a single individual remaining in the wild; this is a seedling. It is a federally listed endangered species of the United States.
Stenogyne campanulata is a rare species of flowering plant in the mint family known by the common name Kalalau Valley stenogyne. It is endemic to Hawaii, where it is known only from the Kalalau Valley on the island of Kauai. It is a federally listed endangered species of the United States.
Stenogyne kealiae is a rare species of flowering plant in the mint family known by the common name Keal's stenogyne. It is endemic to Hawaii, where it is known only from the island of Kauai. It was federally listed as an endangered species of the United States in 2010.
Trematolobelia singularis, the lavaslope false lobelia, is a rare species of flowering plant in the bellflower family. It is endemic to Hawaii, where it is known only from the Koʻolau Range on the island of Oahu. It is threatened by the degradation of its habitat. It is a federally listed endangered species of the United States.
Viola chamissoniana is a species of flowering plant in the violet family known by the common name 'olopu. It is endemic to Hawaii, where it is known from the islands of Kauai, Oahu, Molokai, and Maui.
