''Heliotropium arboreum'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the

borage Borage ( or ; ''Borago officinalis''), also known as starflower, is an annual herb in the flowering plant family Boraginaceae native to the Mediterranean region. Although the plant contains small amounts of pyrrolizidine alkaloids, some parts ar ...

family,

Boraginaceae Boraginaceae, the Borago, borage or forget-me-not family, includes about 2,000 species of shrubs, trees, and herbs in 146 to 154 genus, genera with a worldwide distribution. The APG IV system from 2016 classifies the Boraginaceae as single famil ...

. It is native to tropical Asia including southern China,

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

, northern Australia, and most of the

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most ...

s and high islands of

Micronesia Micronesia (, ) is a subregion of Oceania, consisting of approximately 2,000 small islands in the Northwestern Pacific Ocean. It has a close shared cultural history with three other island regions: Maritime Southeast Asia to the west, Poly ...

and

Polynesia Polynesia ( , ) is a subregion of Oceania, made up of more than 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are called Polynesians. They have many things in ...

. Common names include velvetleaf soldierbush, tree heliotrope, veloutier, and octopus bush. It is a

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

or small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

typical of

littoral zone The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely flood ...

s reaching a height of , with a spread of about .

Taxonomy

Originally published as ''Tournefortia argentea'', it was transferred to ''Argusia argentea'', and remained under that name until recently. It was subsequently restored to the genus ''

Tournefortia ''Tournefortia'', often called soldierbushes, is a genus of flowering plants in the borage family, Boraginaceae. It was first published under the name "Pittonia" by Charles Plumier in 1703, in honour of Joseph Pitton de Tournefort, Carl Linnaeu ...

'' before being transferred into the genus ''

Heliotropium ''Heliotropium'' is a genus of flowering plants traditionally included in the family Boraginaceae ''s.l.'', but placed in the family Heliotropiaceae within the Boraginales order, by the Boraginales Working Group.. There are around 325 species ...

'' under a new name in 2003.

Botanical description

The tree heliotrope is a small to medium sized growing tree that typically reaches heights of . The leaves of this tree are light green in color, silvery in sheen, and silky in texture. The tree produces small fruits and flowers during its bloom, (May through November). The flowers are tiny, reaching only in diameter, white, and do not begin to appear until the tree has reached a few years of age. The fruits it produces are small, opaque and fleshy. The bark is light gray/brown and is corrugated. File:Tree heliotrope good license.jpg, Tree heliotrope grove in Hawaii File:Heliotropium Foertherianum 01.JPG, Closeup of leaves and flowers File:Flower of Heliotropium Foertherianum.jpg, Flower

Uses

Wood

The wood of ''H. arboreum'' is commonly used to make handicrafts, tools, and, in Polynesia, frames for swim

goggles Goggles, or safety glasses, are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and ...

. Due to its availability, ''H. arboreum'' is used as

firewood Firewood is any wooden material that is gathered and used for fuel. Generally, firewood is not heavily processed, and is in some sort of firelog, recognizable log or branch form, compared to other forms of wood fuel like pellet fuel, pellets. ...

, and has become rare in some areas as a result.Manner, Harley I. "Tournefortia Argentea (Tree Heliotrope)". ''Species Profile for Pacific Island Agroforestry'', Apr. 2006

Leaves

In the Marshall Islands, corpses are washed in water soaked with the leaves of the tree heliotrope to mask smells. The leaves are used as a spice on some islands, and can also be eaten raw as a salad. In Kiribati, oil from the leaves is used to make deodorant.Montoya, John Edward, and Richard Criley. "Expanding Tree Diversity in Hawai'i's Landscapes: Beach Heliotrope, Tournefortia Argentea". University of Hawai'i, Mar. 2014.

Medicinal

Octopus bush is used in many Pacific islands as a traditional medicine to treat ciguatera fish poisoning, which is caused by powerful

ciguatoxin image:ciguatoxin.svg, 300px, class=skin-invert-image, Chemical structure of the ciguatoxin CTX1B Ciguatoxins are a class of toxic Polycyclic compound, polycyclic polyethers found in fish that cause ciguatera. There are several different chemi ...

s produced by microscopic ''

Gambierdiscus ''Gambierdiscus'' is a genus of marine dinoflagellates that produce ciguatoxins, a type of toxin that causes the foodborne illness known as ciguatera. They are usually epiphytic on macroalgae growing on coral reefs. Morphology ''Gambierdiscus' ...

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

. Scientists from the Institute of Research for Development (IRD) and the Louis Malarde Institute in French Polynesia and Pasteur Institute in New Caledonia are researching the plant chemistry and believe that senescent leaves contain

rosmarinic acid Rosmarinic acid, named after rosemary (''Salvia rosmarinus'' Spenn.), is a polyphenol constituent of many culinary herbs, including rosemary (''Salvia rosmarinus'' L.), perilla (''Perilla frutescens'' L.), sage (''Salvia officinalis'' L.), min ...

and derivatives, which are known for its

antiviral Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Antiviral drugs are a class of antimicrobials ...

antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

, and

anti-inflammatory Anti-inflammatory is the property of a substance or treatment that reduces inflammation, fever or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs reduce pain by inhibiting mechan ...

properties. The researchers think that rosmarinic acid removes the ciguatoxins from their sites of action, as well as being an anti-inflammatory agent.

Coastal protection

The preferred growing conditions of ''H. arboreum'' are in the littoral zone. It thrives in sandy barren soil with high drainage. It is capable of withstanding sea spray, and can grow in heavy winds. The tree is also a drought resistant variety, allowing it to survive the subtropical dry season of the South Pacific. These factors, plus the roots of ''H. arboreum'' taking hold in the sand, help stabilize the shore, mitigating coastal erosion.

References

External links

Plants of Midway Atoll
{{Taxonbar, from=Q2065214 arboreum Flora of the Australasian realm Eudicots of Western Australia Flora of Ashmore and Cartier Islands Flora of Christmas Island Flora of India (region) Flora of Malesia Flora of Queensland Flora of the Coral Sea Islands Territory Flora of the Maldives Flora of the Northern Territory Flora of the Pacific Flora of the Tubuai Islands Flora of the Western Indian Ocean Flora of Vietnam Flora of the Indomalayan realm Lamiales of Australia Leaf vegetables Least concern biota of Asia Least concern biota of Queensland Least concern flora of Australia Least concern flora of Oceania Least concern plants Flora of the Oceanian realm Taxonomy articles created by Polbot Trees of Australia