''Malva arborea'' (previously known as ''Lavatera arborea'', or, more recently as ''Malva eriocalyx''), the tree mallow, is a species of mallow native to the

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

s of western

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and the Mediterranean region, from

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

and

Britain Britain most often refers to: * Great Britain, a large island comprising the countries of England, Scotland and Wales * The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...

south to

Algeria Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...

and

Libya Libya, officially the State of Libya, is a country in the Maghreb region of North Africa. It borders the Mediterranean Sea to the north, Egypt to Egypt–Libya border, the east, Sudan to Libya–Sudan border, the southeast, Chad to Chad–L ...

, and east to

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

.Malvaceae Pages
''Lavatera arborea''
/ref>Flora Europaea
''Lavatera arborea''
/ref>''Botanica. The Illustrated AZ of over 10000 garden plants and how to cultivate them'' p. 514. Könemann, 2004.

Description

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 ...

by annual,

biennial Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years. In particular, it can refer to: * Biennial plant, a plant which blooms in its second year and t ...

perennial plant In horticulture, the term perennial (''wikt:per-#Prefix, per-'' + ''wikt:-ennial#Suffix, -ennial'', "through the year") is used to differentiate a plant from shorter-lived annual plant, annuals and biennial plant, biennials. It has thus been d ...

growing to 0.5–2 m (rarely 3 m) tall. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are orbicular, 8–18 cm diameter, palmately lobed with five to nine lobes, and a coarsely serrated margin. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are 3–4 cm diameter, dark pink to purple and grow in fasciculate axillary clusters of two to seven.

Taxonomy

It was first named in 1753 by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

as ''Lavatera arborea'', but was transferred to the genus ''

Malva ''Malva'' is a genus of herbaceous annual, biennial, and perennial plants in the family Malvaceae. It is one of several closely related genera in the family to bear the common English name mallow. The genus is widespread throughout the temp ...

'' in 1836 by

Philip Barker-Webb Philip Barker Webb (10 July 1793 – 31 August 1854) was an English botanist. Life Webb was born to a wealthy, aristocratic family; his father was the lord of the manors of Witley and Milford, in Surrey, England. Webb was educated at Harr ...

and

Sabin Berthelot Sabin Berthelot (4 April 1794 – 10 November 1880) was a French naturalist and ethnologist. He was a resident of the Canary Islands for part of his life, and co-authored ''L'Histoire Naturelle des Îles Canaries'' (1835–50) with Philip Barker ...

. Although long considered a species of '' Lavatera'', genetic and morphological analysis by Martin Forbes Ray, reported in 1998, suggested it was better placed in the genus ''

'', in which it was named ''Malva dendromorpha'' M.F.Ray. However the earlier name ''Malva arborea'' (L.) Webb & Berthel. was validly published and has priority over ''Malva dendromorpha''.

Habitat

''Malva arborea'' tolerates sea water to varying degrees, at up to 100% sea water in its natural habitat, excreting salt through glands on its leaves.Veitch, C. R., and Michael Norman Clout (editors). (2002.
''Turning the Tide: The Eradication of Invasive Species'': Proceedings of the International Conference on Eradication of Island Invasives.
The World Conservation Union (IUCN): Gland, Switzerland and Cambridge, UK, pp. 254–259. . Retrieved on 2007-09-28.Okusanya, O. T., and T. Fawole. (March 1985.
The Possible Role of Phosphate in the Salinity Tolerance of Lavatera Arborea.
The Journal of Ecology, Vol. 73, No. 1, pp. 317–322, , Retrieved on 2007-09-28. This salt tolerance can be a competitive advantage over inland plant species in coastal areas. Its level of

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

tolerance is thought to be improved by soil with higher

phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

content, making

guano Guano (Spanish from ) is the accumulated excrement of seabirds or bats. Guano is a highly effective fertiliser due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. Guano was also, to a le ...

enrichment particularly beneficial. It grows mainly on exposed coastal locations, often on small

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

s, only rarely any distance inland.Nico Vermeulen: ''The Complete Encyclopedia of Container Plants'' p. 158. Rebo International, Netherlands, 1998. Blamey, M. & Grey-Wilson, C. (1989). ''Flora of Britain and Northern Europe''. Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan .

Uses

The leaves of the species are used in herbal medicine to treat sprains, by steeping them in hot water and applying the

poultice A poultice or cataplasm, also called a fomentation, is a soft moist mass, often heated and medicated, that is applied to the skin to reduce inflammation, soothe pain, promote healing, or otherwise treat wounds or ailments. Soft materials like cer ...

to the affected area. It is theorised that

lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Ligh ...

keepers may have spread the plant to some British islands for use as a poultice and to treat burns, an occupational hazard. Thought to have been used as an alternative to toilet paper. The seeds are edible and are known in French as "petit pains", or "little breads". Tree mallow was considered a nutritive animal food in Britain in the 19th century, and is still sometimes used as animal

fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food ...

in Europe. For human consumption, some sources describe the leaves of tree mallow as edible, although not as palatable as common mallow, unless cut very thinly, because of the very velours-like hairy mouth-feel. ''Malva arborea'' has long been cultivated in British gardens, as described in the 1835 self-published book ''British Phaenogamous Botany'', which used the then-common name ''Sea Tree-mallow'': "This species is frequently met with in gardens, where, if it is allowed to scatter its seeds, it will spring up for many successive years, and often attain a large size. The young plants will, as Sir J. E. Smith observes, now and then survive one or more mild Winters; but having once blossomed it perishes."Baxter, William. (1835)
''British Phaenogamous Botany, Or, Figures and Descriptions of the Genera of British Flowering Plants'' Vol. II.
(Self-published): Oxford, pp. 112-113. Retrieved on 2007-09-28. While sometimes detrimental to seabird habitat, management of tree mallow (both planting and thinning) has been successfully employed to shelter nesting sites of the threatened

roseate tern The roseate tern (''Sterna dougallii'') is a species of tern in the family Laridae. The genus name ''Sterna'' is derived from Old English "stearn", "tern", and the specific ''dougallii'' refers to Scottish physician and collector Dr Peter McD ...

, which requires more coverage than

common tern The common tern (''Sterna hirundo'') is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in Temperateness, temperate and subarctic regions of Europe, Asia and North America. It is stron ...

s to impede predation.

Invasive spread

Tree mallow seeds may be transported between separated coastal areas by the floating fruit, and seabirds are considered a likely means of spread. The seeds are encased in an impermeable outer case, and can remain viable for years, even after extended immersion in saltwater. The tree mallow's recent increased range among Scottish islands has raised concerns that it is displacing native vegetation, and is reducing

Atlantic puffin The Atlantic puffin ('), also known as the common puffin, is a species of seabird in the auk family (biology), family. It is the only puffin native to the Atlantic Ocean; two related species, the tufted puffin and the horned puffin being found ...

(''Fratercula arctica'') populations in affected areas. The plant forms dense stands along the island coasts that inhibit breeding, and causes the puffins to abandon their burrows.Invasion of Scottish seabird islands by tree mallow.
(Website.) Centre for Ecology and Hydrology, UK Natural Environment Research Council. Retrieved on 2007-09-28. Its spread among Australian islands in recent decades is thought to be reducing biodiversity, soil retention, and seabird habitat. According to one study, "Crested and Caspian Terns that nest in the open are closed out by the canopy, and Little Penguins (''Eudyptula minor'') and Bridled Terns (''Sterna anaethetus'') are excluded by the lack of undergrowth". In New Zealand it has established on several seabird-dominated islands where it is considered to be a serious ecological weed and for which there are active eradication programmes, such as on North Brother Island in Cook Strait.

References

External links

{{Taxonbar, from1=Q12210226, from2=Q811549

arborea Arborea is a town and ''comune'' in the province of Oristano, Sardinia, Italy, whose economy is largely based on agriculture and cattle breeding with production of vegetables, rice, fruit and milk (notably the local milk product Arborea). Histo ...

Flora of Europe Flora of North Africa Plants described in 1753 Taxa named by Carl Linnaeus Garden plants of Europe