Eugenia koolauensis, commonly known as Koʻolau eugenia or nioi, is a species of flowering plant in the myrtle family, Myrtaceae. It is endemic to Hawaii, where it could previously be found on the islands of Molokaʻi and Oʻahu; today populations only exist on the latter. This is a federally listed endangered species of the United States.
Sapindus oahuensis is a species of tree in the soapberry family, Sapindaceae. It is endemic to Hawaii, where it is limited to Kauaʻi and Oʻahu. Its common names include Āulu, Oahu soapberry, alulu, kaulu, and lonomea.
Euphorbia rockii is a rare species of flowering plant in the euphorb family known by the common names Koolau Range sandmat and Rock's broomspurge. It is endemic to Oʻahu, Hawaii, where it is known only from the Koʻolau Mountains. There are 200 to 300 plants remaining. Like other Hawaiian euphorbs, this plant is known locally as ʻakoko.
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 humboldtiana is a rare species of flowering plant in the bellflower family known by the common name Oʻahu rollandia. It is native to Oʻahu, where it is known only from the Koʻolau Mountains. It is a federally listed endangered species. Like other Cyanea it is known as haha in Hawaiian.
Cyanea st.-johnii is a rare species of flowering plant in the bellflower family known by the common name St. John's rollandia. It is endemic to Oahu, where it is known only from the Koʻolau Mountains. 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.
Cyrtandra crenata is a rare species of flowering plant in the African violet family known by the common name Kahana Valley cyrtandra. It is endemic to Oahu in Hawaii, where it is known only from the Koolau Mountains. It has not been seen since 1947, however, and it is feared extinct. The habitat is steep and inaccessible in some areas, so it is possible that specimens of this species still exist in the wild. It was federally listed an endangered species of the United States in 1994. This shrub grows 1 to 2 meters tall and bears white flowers. Like other Hawaiian Cyrtandra it is called ha`iwale.
Cyrtandra polyantha is a rare species of flowering plant in the African violet family known by the common names Niu Valley cyrtandra. It is endemic to the Hawaii, where it is known only from the Koʻolau Mountains of Oahu. In 2007 there were only two populations containing a total of 46 mature plants, but one of the two populations is made up of a single individual. It was federally listed as an endangered species in 1994. Like other Hawaiian Cyrtandra it is called ha`iwale.
Cyrtandra subumbellata is a rare species of flowering plant in the African violet family known by the common name parasol cyrtandra. It is endemic to Hawaii, where it is known only from the Koʻolau Mountains on the island of Oahu. By 2008 there were three known populations containing 110 plants, or possibly more. It was federally listed as an endangered species in 1996. Like other Hawaiian Cyrtandra it is called ha`iwale.
Cyrtandra viridiflora is a rare species of flowering plant in the African violet family. It is endemic to Hawaii, where it is known only from the northern Koolau Mountains of Oahu. By 2003 there were nine small populations remaining, for a total of 69 plants. It was federally listed as an endangered species in 1996. Like other Hawaiian Cyrtandra it is called ha`iwale.
Delissea subcordata is a rare species of flowering plant in the bellflower family 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.
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.
Lobelia oahuensis is a rare species of flowering plant in the bellflower family known by the common name Oahu lobelia. It is endemic to Hawaii, where it is known only from the island of Oahu. There are about 100 individuals remaining in the Koʻolau Range, and only one known individual in the Waianae Range. It is federally listed as an endangered 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.
Melicope lydgatei is a rare species of flowering plant in the citrus family known by the common names Koolau Range melicope and Lydgate's pelea. It is endemic to Hawaii, where it is known only from the Koolau Range on the island of Oahu. It is a federally listed endangered species of the United States. Like other Hawaiian Melicope, this species is known as alani.
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.
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 kauaensis is a rare species of flowering plant in the violet family known by the common names Kauai violet and pohe hiwa. It is endemic to Hawaii, where it is known from Kauai and Oahu.
