''Quercus lusitanica'', commonly known as gall oak, Lusitanian oak, or dyer's oak, is a species of oak native to

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

( Galicia and western

Andalucia Andalusia (, ; es, Andalucía ) is the southernmost autonomous community in Peninsular Spain. It is the most populous and the second-largest autonomous community in the country. It is officially recognised as a "historical nationality". The t ...

) and

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

. ''Quercus lusitanica'' is the source of commercial nutgalls. These

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

s are produced by the infection from the insect '' Cynips gallae tinctoriae''. They are used for

dyeing Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular ...

. Several other species are known colloquially as "gall oaks;" indeed, galls can be found on a large percentage of oak species. The specific epithet "''lusitanica''" refers to the ancient Roman Province of

Lusitania Lusitania (; ) was an ancient Iberian Roman province located where modern Portugal (south of the Douro river) and a portion of western Spain (the present Extremadura and the province of Salamanca) lie. It was named after the Lusitani or Lusita ...

, corresponding roughly to present-day Portugal and

Extremadura Extremadura (; ext, Estremaúra; pt, Estremadura; Fala: ''Extremaúra'') is an autonomous community of Spain. Its capital city is Mérida, and its largest city is Badajoz. Located in the central-western part of the Iberian Peninsula, it ...

in Spain.

Description

''Quercus lusitanica'' is an evergreen creeping bush, rarely exceeding in height and is often no taller than . The plant mainly spreads through various suckers.

Taxonomy

It was incorrectly named ''Q. humilis'', later ''Q. fruticosa'' and its current name was incorrectly used to identify other Gall oaks from the Iberian Peninsula and North Africa. This resulted in numerous taxonomy errors in the Gall oaks taxa from the occidental and oriental

Mediterranean Basin In biogeography, the Mediterranean Basin (; also known as the Mediterranean Region or sometimes Mediterranea) is the region of lands around the Mediterranean Sea that have mostly a Mediterranean climate, with mild to cool, rainy winters and w ...

Distribution and habitat

''Quercus lusitanica'' is native to the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...

(in Portugal and western

Andalusia Andalusia (, ; es, Andalucía ) is the southernmost Autonomous communities of Spain, autonomous community in Peninsular Spain. It is the most populous and the second-largest autonomous community in the country. It is officially recognised as a ...

, Spain, also rare on Galicia) and Morocco It is commonly associated in oak and pine forests and does well in acidic soils. It favors mild coastal

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

s but it also succeeds in moist, mild,

maritime climate An oceanic climate, also known as a marine climate, is the humid temperate climate sub-type in Köppen classification ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring cool summers and mild winters ...

s. It is relatively sensitive to cold temperatures and is hardy down to . It inhabits sandy or gravelly soils up to in elevation.

Threats

No serious threats were found in Portugal, though in Andalusia this plant has been listed as

Near Threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

due to fires, silviculture and grazing

ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, cam ...

s. The main threat to the conservation of genetic diversity of this species is the hybridization with the oak neighbors (

Holm Oak Holm oak may refer to: * '' Quercus ilex'', tree native to South and Southeast Europe and parts of France * '' Quercus rotundifolia'', tree native to the Iberian Peninsula and Northwest Africa * ''Quercus agrifolia ''Quercus agrifolia'', the Cal ...

Cork Oak ''Quercus suber'', commonly called the cork oak, is a medium-sized, evergreen oak tree in the section ''Quercus'' sect. ''Cerris''. It is the primary source of cork for wine bottle stoppers and other uses, such as cork flooring and as the cores ...

Kermes Oak ''Quercus coccifera'', the kermes oak, is an oak bush in the ''Ilex'' section of the genus. It is native to the Mediterranean region and Northern African Maghreb, south to north from Morocco to France and west to east from Portugal to Cyprus an ...

Pyrenean Oak ''Quercus pyrenaica'', commonly known as Pyrenean oak, is a tree native to southwestern Europe and northwestern North Africa. Despite its common name, it is rarely found in the Pyrenees Mountains and is more abundant in northern Portugal and nort ...

References

lusitanica Flora of Spain Flora of Portugal Trees of Morocco Trees of Mediterranean climate Oak galls Plants described in 1785 Plant dyes {{Quercus-stub