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.
Cordylanthus rigidus is a species of flowering plant in the family Orobanchaceae known by the common name stiffbranch bird's beak.
Clermontia oblongifolia is a species of flowering plant in the bellflower family known by the common name Oahu clermontia. It is one of several Hawaiian lobelioids in genus Clermontia that are known as ʻoha wai. This plant is native to three of the Hawaiian Islands, where one subspecies is not uncommon but the other two are very rare and endangered.
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.
Diplazium molokaiense is a rare species of fern known by the common name Molokai twinsorus fern. It is endemic to Hawaii, where it is one of the rarest ferns. It has historically been found on the islands of Kauai, Oahu, Lanai, Molokai, and Maui, but it is thought to have been extirpated from four of them and today can be found only on Maui where fewer than 70 individual plants remain. The fern was federally listed as an endangered species of the United States in 1994.
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.
Kadua coriacea is a rare species of flowering plant in the coffee family known by the common name kioʻele. It is endemic to Hawaii, where it is known only from the island of Hawaiʻi and one individual remaining on Maui. 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.
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.
Plantago princeps is a rare species of flowering plant in the plantain family known by the common name ale. It is endemic to Hawaii, where it is known from the islands of Hawaii, Kauai, Oahu, Molokai, and Maui. Like other Hawaiian Plantago, it is known as kuahiwi laukahi, or laukahi kuahiwi. 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 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.
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.
Spermolepis hawaiiensis is a rare species of flowering plant in the carrot family known by the common name Hawai'i scaleseed. It is endemic to Hawaii, where it is known from the islands of Kauai, Maui, Oahu, Molokai, Lanai, and Hawaii. It is threatened by the degradation of its habitat and it is a federally listed endangered species.
Stenogyne kanehoana is a rare species of flowering plant in the mint family known by the common name Oahu stenogyne. It is endemic to Hawaii, where it is known only from the Waianae Range on the island of Oahu. It is a federally listed endangered species of the United States.
Tetramolopium lepidotum is a rare species of flowering plant in the family Asteraceae known by the common name Waianae Range tetramolopium. It is endemic to Hawaii, where today it is known only from the Waianae Mountains on the island of Oahu. It is threatened by habitat degradation caused by feral goats and pigs and introduced species of plants.
Vigna owahuensis is a rare species of flowering plant in the legume family known by the common name Oahu cowpea.
Viola renifolia is a species of violet known by the common names white violet and kidneyleaf violet. It is native to northern North America, where it has a widespread distribution across Canada and the northern United States as far south as Washington, Colorado, and New York.
