Hibiscadelphus woodii is a species of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 in the mallow

Malva

Malva is a genus of about 25–30 species of herbaceous annual, biennial, and perennial plants in the family Malvaceae , one of several closely related genera in the family to bear the common English name mallow. The genus is widespread throughout the temperate, subtropical and tropical regions of...

 family, Malvaceae

Malvaceae

Malvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...

, that is endemic to Kauai

Kauai

Kauai or Kauai, known as Tauai in the ancient Kaua'i dialect, is geologically the oldest of the main Hawaiian Islands. With an area of , it is the fourth largest of the main islands in the Hawaiian archipelago, and the 21st largest island in the United States. Known also as the "Garden Isle",...

, Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

. It is a small tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

, reaching a height of 2.5–5 m (8.2–16.4 ft).

It was discovered in 1991 and described as a new species in 1995.

H. woodii inhabits basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

 scree

Scree

Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...

 and cliff walls in ōhia lehua (Metrosideros polymorpha

Metrosideros polymorpha

The ōhia lehua is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations, and much smaller when growing in boggy soils or on basalt...

) dominated mixed mesic forests at an elevation of 915 m (3,002 ft). Associated plants include kookoolau (Bidens

Bidens

Bidens is a genus of flowering plants in the family Asteraceae. It contains about 200 species. The common names beggarticks, black jack, bur-marigolds, stickseeds, tickseeds and tickseed sunflowers refer to the achene burrs on the seeds of this genus, most of which are barbed...

 sandvicensis), āhinahina (Artemisia australis), alani (Melicope pallida

Melicope pallida

Melicope pallida is a species of tree in the Rutaceae family. It is endemic to the Hawaiian Islands. It is threatened by habitat loss. It is a federally listed endangered species of the United States. Like other Hawaiian Melicope, this species is known as alani.This tree grows up to ten meters in...

), naenae (Dubautia

Dubautia

Dubautia is a genus of flowering plant in the sunflower family, Asteraceae, that is endemic to Hawaii. It contains more species than the other two genera in the silversword alliance, including cushion plants, shrubs, trees, and lianas.-Selected species:...

spp.), ānaunau (Lepidium

Lepidium

Lepidium is a genus of plants in the mustard family Brassicaceae. It includes about 175 species found worldwide, including cress and pepperweed; additional common names include peppercress, peppergrass, and pepperwort...

 serra), nehe (Lipochaeta

Lipochaeta

Lipochaeta is a genus of flowering plants in the daisy family, Asteraceae.-Selected species:*Lipochaeta connata DC. – Nehe *Lipochaeta degeneri Sherff – Molokai Nehe...

spp.), kolokolo kuahiwi (Lysimachia

Lysimachia

Lysimachia is a genus of flowering plants. It is traditionally classified in the family Primulaceae but should, according to molecular phylogenetic study, be placed to the family Myrsinaceae .-Characteristics:...

 glutinosa), Carex

Carex

Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...

 meyenii, akoko (Euphorbia spp.), manono (Hedyotis

Hedyotis

Hedyotis is a genus of flowering plants in the family Rubiaceae. Many species of this genus such as Hedyotis biflora, H. corymbosa and H. diffusa are well known medicinal plants. The hedyotis is native to tropical and subtropical Asia and to islands of the northwest Pacific. It comprises about...

spp.), kuluī (Nototrichium

Nototrichium

Nototrichium is a genus of flowering plants in the pigweed family, Amaranthaceae. All members of the genus are endemic to the Hawaiian Islands. They are known in Hawaiian as kuluī.-Species:*Nototrichium divaricatum Lorence...

spp.), Panicum

Panicum

Panicum is a large genus of about 450 species of grasses native throughout the tropical regions of the world, with a few species extending into the northern temperate zone...

 lineale, kōlea (Myrsine

Myrsine

Myrsine is a genus of flowering plants, the nominate genus of the family Myrsinaceae. It is found nearly worldwide, primarily in tropical and subtropical areas...

spp.), Stenogyne

Stenogyne

Stenogyne is a genus of flowering plants in the mint family. It is endemic to Hawaii.Species include:*Stenogyne angustifolia - narrowleaf stenogyne*Stenogyne bifida - twocleft stenogyne*Stenogyne calaminthoides - bog stenogyne...

 campanulata

Stenogyne campanulata

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...

, Lobelia niihauensis

Lobelia niihauensis

Lobelia niihauensis is a rare species of flowering plant in the bellflower family known by the common name Niihau lobelia. It is endemic to Hawaii, where it is known only from the islands of Oahu and Kauai. It is thought to be extirpated from Niihau...

, and Mann's Bluegrass (Poa

Poa

Poa is a genus of about 500 species of grasses, native to the temperate regions of both hemispheres. Common names include meadow-grass , bluegrass , tussock , and speargrass. "Poa" is Greek for fodder...

 mannii

Poa mannii

Poa mannii is a rare species of grass known by the common names Mann's bluegrass and Olokele Gulch bluegrass. It is endemic to Hawaii, where it is limited to the island of Kauai. It is threatened by the loss and modification of its habitat...

). It is threatened by habitat loss, and only two plants are known to exist in the wild.