Euphorbia halemanui
Encyclopedia
Euphorbia halemanui is a rare species of flowering plant in the euphorb family
known by the common name Kauai sandmat. It is endemic to Kauai
, Hawaii
, where there are no more than 400 plants remaining. There are four populations at last count. It is a federally listed endangered species
.
This is a shrub
with vining, climbing stems that bleed a milky sap
. The inflorescence
is a single cyathium
or a dense cluster of many. It and other Hawaiian euphorbs perform C4 carbon fixation
.
This rare plant grows in moist forested slopes on Kauai. The forests are often dominated by koa (Acacia koa) and ōhia lehua
(Metrosideros polymorpha). In other areas it grows alongside kauila
(Alphitonia ponderosa), hame
(Antidesma platyphyllum), aalii
(Dodonaea viscosa), Kauai kokio
(Kokia kauaiensis), and other native plants.
Euphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
known by the common name Kauai sandmat. It 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...
, where there are no more than 400 plants remaining. There are four populations at last count. 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...
.
This is a 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 vining, climbing stems that bleed a milky sap
Sap
Sap may refer to:* Plant sap, the fluid transported in xylem cells or phloem sieve tube elements of a plant* Sap , a village in the Dunajská Streda District of Slovakia...
. 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 single cyathium
Cyathium
A cyathium is one of the specialised pseudanthia forming the inflorescence of plants in the genus Euphorbia . A cyathium consists of:...
or a dense cluster of many. It and other Hawaiian euphorbs perform C4 carbon fixation
C4 carbon fixation
C4 carbon fixation is one of three biochemical mechanisms, along with and CAM photosynthesis, used in carbon fixation. It is named for the 4-carbon molecule present in the first product of carbon fixation in these plants, in contrast to the 3-carbon molecule products in plants. fixation is an...
.
This rare plant grows in moist forested slopes on Kauai. The forests are often dominated by koa (Acacia koa) and ōhia 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). In other areas it grows alongside kauila
Alphitonia ponderosa
Alphitonia ponderosa is a species of flowering tree in the buckthorn family, Rhamnaceae, that is endemic to the Hawaiian Islands. It is locally known as kauila, as is the related Colubrina oppositifolia.-Description:A...
(Alphitonia ponderosa), hame
Antidesma platyphyllum
Antidesma platyphyllum is a species of flowering tree in the leafflower family, Phyllanthaceae, that is endemic to Hawaii. Common names include Hame, Haa, Mehame, Hamehame, Mehamehame, and Haāmaile. It inhabits coastal mesic forests, mixed mesic forests, wet forests, and bogs at elevations of on...
(Antidesma platyphyllum), aalii
Dodonaea viscosa
Dodonaea viscosa is a species of flowering plant in the soapberry family, Sapindaceae, that has a cosmopolitan distribution in tropical, subtropical and warm temperate regions of Africa, the Americas, southern Asia and Australasia.-Description:...
(Dodonaea viscosa), Kauai kokio
Kokia kauaiensis
Kokia kauaiensis, the Kauai Kokio, is a species of flowering plant in the mallow family, Malvaceae, that is endemic to Kauai, Hawaii.It inhabits coastal mesic and mixed mesic forests at elevations of...
(Kokia kauaiensis), and other native plants.