Kadua cookiana
Encyclopedia
Kadua cookiana is a rare species of flowering plant in the coffee family
known by the common names 'awiwi and Cook's bluet. It is endemic to Hawaii
, where it is known only from Kauai
, having been extirpated
from Molokai
and Hawaii
. It is a federally listed endangered species
of the United States.
Today there are two populations of the plant in the Hanakoa
and Waiahuakua Valleys on the Nā Pali Coast
of Kauai, with a total global population of no more than 122 individuals. The plant grows next to flowing water, particularly waterfall
s, where it grows from cracks in basalt
walls next to the falling water. Other plants in the habitat include ahinahina (Artemisia australis), kookoolau (Bidens forbesii, akoko (Chamaesyce celastroides var. hanapepensis), kikawaio (Christella cyatheoides), 'uiwi (Kadua elatior), and uki (Machaerina angustifolia).
This is a small shrub
with many short branches up to 20 centimeters long and lined with narrow leaves. It bears white flowers. It is gynodioecious
, with an individual plant bearing either bisexual or all female flowers.
Threats to this rare species include habitat damage and destruction by feral pigs and introduced plant species
. Plants may be lost in flood
s, hurricanes, and landslides.
Rubiaceae
The Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...
known by the common names 'awiwi and Cook's bluet. It is endemic to 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...
, where it is known only from 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",...
, having been extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
from Molokai
Molokai
Molokai or Molokai is an island in the Hawaiian archipelago. It is 38 by 10 miles in size with a land area of , making it the fifth largest of the main Hawaiian Islands and the 27th largest island in the United States. It lies east of Oahu across the 25-mile wide Kaiwi Channel and north of...
and Hawaii
Hawaii (island)
The Island of Hawaii, also called the Big Island or Hawaii Island , is a volcanic island in the North Pacific Ocean...
. It is a federally listed endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of the United States.
Today there are two populations of the plant in the Hanakoa
Hanakoa Valley
Hanakoa Valley is a hanging valley along the Kalalau Trail along the Nā Pali Coast of the island of Kauai in the state of Hawaii. Hanakoa has primitive camping via permit only. It is located on mile 6 of the Kalalau Trail, often used as a resting destination for hikers completing the Kalalau Trail...
and Waiahuakua Valleys on the Nā Pali Coast
Na Pali Coast State Park
Nā Pali Coast State Park encompasses of land and is located in the center of the rugged along the northwest side of Kauai, the oldest inhabited Hawaiian island. The Nā Pali coast itself extends southwest starting at Kee Beach extending all the way to Polihale State Park. The pali rise as high as...
of Kauai, with a total global population of no more than 122 individuals. The plant grows next to flowing water, particularly waterfall
Waterfall
A waterfall is a place where flowing water rapidly drops in elevation as it flows over a steep region or a cliff.-Formation:Waterfalls are commonly formed when a river is young. At these times the channel is often narrow and deep. When the river courses over resistant bedrock, erosion happens...
s, where it grows from cracks in 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...
walls next to the falling water. Other plants in the habitat include ahinahina (Artemisia australis), kookoolau (Bidens forbesii, akoko (Chamaesyce celastroides var. hanapepensis), kikawaio (Christella cyatheoides), 'uiwi (Kadua elatior), and uki (Machaerina angustifolia).
This is a small shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
with many short branches up to 20 centimeters long and lined with narrow leaves. It bears white flowers. It is gynodioecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
, with an individual plant bearing either bisexual or all female flowers.
Threats to this rare species include habitat damage and destruction by feral pigs and introduced plant species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
. Plants may be lost in flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
s, hurricanes, and landslides.