The Kalalau Valley is located on the northwest side of the island of Kauaʻi in the state of Hawaiʻi. The valley is located in the Nā Pali Coast State Park and houses the Kalalau Beach. The Nā Pali Coast is rugged and is inaccessible to automobiles. The only legal ways to access the valley are by kayak or by hiking the Kalalau Trail.
Cyanea dolichopoda was a species of shrub in the bellflower family that was endemic to Kauai. It was discovered in 1990 and has not been located in the wild since 1992. Like other Cyanea it is known as haha in Hawaiian.
Cyanea kolekoleensis is a rare species of flowering plant in the bellflower family known by the common names `Oha and Kolekole cyanea. It is endemic to Kauai where it has only been seen in the Wahiawa Mountains. Like other Cyanea it is known as haha in Hawaiian.
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.
Dubautia imbricata is a rare species of flowering plant in the family Asteraceae known by the common names bog dubautia and imbricate dubautia. It is endemic to Hawaii where it is known only from the island of Kauai. There are four known occurrences. Like other Dubautia this plant is known as na`ena`e.
Dubautia kalalauensis is a rare species of flowering plant in the family Asteraceae. It is endemic to Hawaii where it is known only from the island of Kauai. There is only a single known population composed of 26 plants. It was federally listed as an endangered species of the United States in 2010. Like other Dubautia this plant is known as na`ena`e.
Dubautia latifolia is a rare species of flowering plant in the family Asteraceae known by the common name koholapehu. It is endemic to Hawaii where it is known only from the west side of the island of Kauai. Like other Dubautia this plant is called na`ena`e.
Dubautia pauciflorula is a rare species of flowering plant in the family Asteraceae known by the common name Wahiawa Bog dubautia. It is endemic to Hawaii where it is known only from the Wahiawa Mountains on the island of Kauai.
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.
Dubautia waialealae is a rare species of flowering plant in the family Asteraceae known by the common name Wai'ale'ale dubautia. Like other Dubautia this plant is called na`ena`e.
Kadua st-johnii is a rare species of flowering plant in the coffee family known by the common name Nā Pali beach starviolet. It is endemic to Hawaii, where it is known only from the Nā Pali coast of Kauai. It is a federally listed endangered species of the United States.
Melanthera waimeaensis is a rare species of flowering plant in the family Asteraceae known by the common name Waimea Canyon nehe. It is endemic to Hawaii, where it is known only from the island of Kauai. It is federally listed as an endangered 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.
Lysimachia scopulensis is a rare species of flowering plant in the family Primulaceae known by the common name shiny-leaf yellow loosestrife. It is endemic to Hawaii, where there are two small populations on the island of Kauai. It was federally listed as an endangered species of the United States in 2010.
Lysimachia venosa is a rare species of flowering plant in the family Primulaceae known by the common name veined yellow loosestrife. It is endemic to Hawaii, where it is known only from the island of Kauai. The plant was only collected twice, last in 1911, but in 1991, a branch was discovered that had broken off the steep cliffs above the headwaters of the Wailua River. The branch was from a plant of this species and may have fallen from the summit of Mount Waialeale. No more specimens have been found since and the plant may be extinct, but some experts believe it may still exist in unsurveyed parts of the habitat. It was federally listed as an endangered species of the United States in 2010.
Melicope degeneri is a rare species of flowering plant in the family Rutaceae known by the common names Kokee Stream melicope and Degener's pelea. It is endemic to Hawaii, where it is known only from the island of Kauai. It is a federally listed endangered species of the United States. Like other Hawaiian Melicope, this species is known as alani.
Remya montgomeryi is a rare species of flowering plant in the family Asteraceae known by the common name Kalalau Valley remya. It is endemic to Hawaii, where it is known only from the island of Kauai. It is threatened by the degradation of its habitat. 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.
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.
Polyscias flynnii is a plant species endemic to the island of Kauai in Hawaii. It is rare, found only in one population covering about 1 km2 in the Kalalau Valley. It is regarded as threatened. It is threatened by feral goats and non-native plant species in its habitat. It was federally listed as an endangered species of the United States in 2010.
