The Hawaiian lobelioids are a group of flowering plants in the bellflower family, Campanulaceae, all of which are endemic to the Hawaiian Islands. This is the largest plant radiation in the Hawaiian Islands, and indeed the largest on any island archipelago, with over 125 species. The six genera can be broadly separated based on growth habit: Clermontia are typically branched shrubs or small trees, up to 7 metres (23 ft) tall, with fleshy fruits; Cyanea and Delissea are typically unbranched or branching only at the base, with a cluster of relatively broad leaves at the apex and fleshy fruits; Lobelia and Trematolobelia have long thin leaves down a single, non-woody stem and capsular fruits with wind-dispersed seeds; and the peculiar Brighamia have a short, thick stem with a dense cluster of broad leaves, elongate white flowers, and capsular fruits.
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 recta is a rare species of flowering plant in the bellflower family known by the common names upright cyanea and Kealia cyanea. It is endemic to Hawaii, where it is known only from the island of Kauai. It is a federally listed threatened species of the United States. 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.
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.
Isodendrion hosakae is a rare species of flowering plant in the violet family known by the common names cindercone isodendrion and aupaka. It is endemic to Hawaii, where it is known from fewer than 1000 individuals on the island of Hawaii. It is a federally listed endangered species of the United States.
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 pyrifolium is a rare species of flowering plant in the violet family known by the common name wahine noho kula. It is endemic to Hawaii, where it is known only from the island of Hawaii. It is a federally listed 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.
Lysimachia pendens is a rare species of flowering plant in the family Primulaceae known by the common name broad-leaf yellow loosestrife. It is endemic to Hawaii, where there is a single occurrence known on the island of Kauai. It 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.
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.
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.
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.
Silene lanceolata is a rare species of flowering plant in the family Caryophyllaceae known by the common names Kauai catchfly and lanceolate catchfly. It is endemic to Hawaii, where it is known only from Oahu, Molokai, and Hawaii, having been extirpated from Kauai and Lanai. It is threatened by the degradation of its habitat and 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.
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.
Vigna owahuensis is a rare species of flowering plant in the legume family known by the common name Oahu cowpea.
