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 Chinese hibiscus and its numerous hybrids, though the native Hibiscus arnottianus is occasionally planted.
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.
Charpentiera is a flowering plant genus in the family Amaranthaceae. It consists of five species endemic to Hawaiʻi, where they are known as pāpala, and one species found only on the island of Tubuai in the Austral Islands. All species are trees, some reaching more than 10 metres (33 ft) in height. The genus is named for Arsène Charpentier (1781-1818), professor of pharmacy at Antwerp from 1810 to 1814 and at Cherbourg from 1814 to 1816.
Wikstroemia oahuensis, the ʻĀkia or Oʻahu false ohelo, is a species of flowering shrub in the mezereon family, Thymelaeaceae, that is endemic to Hawaiʻi.
Cenchrus agrimonioides is a rare species of grass in the family Poaceae that is endemic to the Hawaiian Islands. Its common names include Kāmanomano and agrimony sandbur. It was formerly distributed throughout the major islands but today it is nearly limited to Oʻahu. Kāmanomano inhabits dry to moist forests and lava plains. It is threatened by competition with non-native plants, predation by ungulates, and wildfire. When this plant became a federally listed endangered species of the United States in 1996 there were fewer than 100 individuals remaining. More recent counts revealed 181 wild individuals on Oʻahu and over 300 more which have been planted to augment the populations. This plant is nearly restricted to the island of Oʻahu, but there are a few individuals known on Maui. A few patches of the grass have been planted on Kahoʻolawe, as well.
Alectryon macrococcus, known as ʻAlaʻalahua or Māhoe in Hawaiian, is a species of flowering tree in the soapberry family, Sapindaceae, that is endemic to Hawaii.
Euphorbia celastroides is a flowering plant in the family Euphorbiaceae. It is referred to by the common name 'akoko by Hawaiians, and is a species of spurge closely related to the poinsettia. This species develops into a round-shape shrub. This species is endemic to the Hawaiian Islands.
Euphorbia remyi is a rare species of flowering plant in the family Euphorbiaceae. It is known by the common name Remy's sandmat locally as ʻakoko. It is endemic to the island of Kauaʻi in Hawaii, where it grows in mixed mesic forests, wet forests and bogs from 150 to 900 m.
Euphorbia skottsbergii is a rare species of flowering plant in the euphorb family known by the common names coastal sandmat and Skottsberg's broomspurge. It is endemic to Hawaii, where it is found in coastal shrublands on Oʻahu, Molokaʻi, Maui, and Kahoʻolawe. Like other Hawaiian euphorbs, this plant is known locally as ʻakoko.
Cyrtandra oenobarba is a rare species of flowering plant in the African violet family known by the common name shaggystem cyrtandra. It is endemic to Hawaii, where it is known only from the island of Kauai. It can be found in only three localized areas of the island and there are fewer than 500 individuals remaining in the wild. It was federally listed as an endangered species in 2010. Like other Hawaiian Cyrtandra it is called ha`iwale.
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.
Phyllostegia parviflora is a rare species of flowering plant in the mint family known by the common name smallflower phyllostegia. It is endemic to Hawaii, where it is known from Maui, Oahu, and the island of Hawaii. It is a federally listed endangered 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.
Platanthera holochila is a rare species of orchid known by the common name Hawaii bog orchid. It is endemic to Hawaii. It is a federally listed endangered species of the United States.
Stenogyne is a genus of flowering plants in the mint family first described in 1830. The entire genus is endemic to Hawaii.
- Stenogyne angustifoliaA.Gray - narrowleaf stenogyne
- Stenogyne bifidaHillebr. - twocleft stenogyne - Molokai
- Stenogyne calaminthoidesA.Gray - bog stenogyne - Big Island
- Stenogyne calycosaSherff - Maui
- Stenogyne campanulataWeller & Sakai - Kalalau Valley stenogyne - Kauai
- †Stenogyne cinereaHillebr - Maui but extinct
- Stenogyne cranwelliaeSherff - Big Island
- †Stenogyne haliakalaeWawra - Maui but extinct
- Stenogyne kaalaeWawra - Oahu
- Stenogyne kamehamehaeWawra - Molokai, Maui
- Stenogyne kanehoanaO.Deg. & Sherff - Oahu stenogyne - Oahu
- Stenogyne kauaulaensisK.R.Wood & H.Oppenh. - Maui
- Stenogyne kealiaeWawra - Kauai
- Stenogyne macranthaBenth. - Big Island
- Stenogyne microphyllaBenth. - Maui, Big Island
- †Stenogyne oxygonaO.Deg. & Sherff - Big Island but extinct
- Stenogyne purpureaH.Mann - Kauai
- Stenogyne rotundifoliaA.Gray - pua'ainaka - Maui
- Stenogyne rugosaBenth. - ma'ohi'ohi - Maui, Big Island
- Stenogyne scrophularioidesBenth. - mohihi - Big Island
- Stenogyne sessilisBenth. - Lanai, Maui, Big Island
- †Stenogyne viridisHillebr. - Maui but extinct
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.
Viola helenae is a rare species of flowering plant in the violet family known by the common name Wahiawa stream violet. It is endemic to Hawaii, where it is known only from the Wahiawa Mountains of Kauai. It is threatened by exotic plant species and feral pigs. It is a federally listed endangered species of the United States.
Viola oahuensis is a rare species of flowering plant in the violet family known by the common name Oahu violet.
Zanthoxylum dipetalum is a rare species of tree in the family Rutaceae and in the same genus as Szechuan pepper. It is known by the Hawaiian names Kāwa'u and Heaʻe and is endemic to the Hawaiian archipelago, where it grows in forests on 3 or 4 of the islands.
