Dubautia imbricata
Encyclopedia
Dubautia imbricata is a rare species of flowering plant in the aster family
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.
This member of the silversword alliance
was first described to science in 1981 after it was discovered in a Kauaian rainforest
. It grows in just a few spots in boggy forest habitat in the understory
of ʻōhiʻa lehua
(Metrosideros polymorpha) trees among sedges
in the genera Oreobolus and Rhynchospora
.
There are two subspecies. Both are rare and ssp. imbricata was federally listed as an endangered species
of the United States in 2010.
This plant is a clumpy, bushy shrub
which reaches 2.5 meters tall by 2 meters wide. The oppositely arranged leaves are up to 15 centimeters long by 2.5 wide. The inflorescence
is a cluster of many flower head
s, each of which contains several yellow flowers.
Both subspecies are known to hybridize with other Dubautia.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
known by the common names bog dubautia and imbricate dubautia. 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 the island of 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",...
. There are four known occurrences. Like other Dubautia this plant is known as na`ena`e.
This member of the silversword alliance
Silversword alliance
Silversword alliance refers to an adaptive radiation of over 50 species in the composite or sunflower family, Asteraceae. The group is endemic to Hawaii, and is derived from a single immigrant to the islands...
was first described to science in 1981 after it was discovered in a Kauaian rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
. It grows in just a few spots in boggy forest habitat in the understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
of ʻōhiʻa lehua
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...
(Metrosideros polymorpha) trees among sedges
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
in the genera Oreobolus and Rhynchospora
Rhynchospora
Rhynchospora is a genus of about 250-300 species of sedges with a cosmopolitan distribution. The genus includes both annual and perennial species, mostly with erect 3-sided stems and 3-ranked leaves...
.
There are two subspecies. Both are rare and ssp. imbricata was federally listed as an 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 in 2010.
This plant is a clumpy, bushy 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...
which reaches 2.5 meters tall by 2 meters wide. The oppositely arranged leaves are up to 15 centimeters long by 2.5 wide. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a cluster of many flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
s, each of which contains several yellow flowers.
Both subspecies are known to hybridize with other Dubautia.