''Quercus estremadurensis'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

in the family

Fagaceae The Fagaceae (; ) are a family of flowering plants that includes beeches, chestnuts and oaks, and comprises eight genera with around 1,000 or more species. Fagaceae in temperate regions are mostly deciduous, whereas in the tropics, many species ...

native Native may refer to: People * '' Jus sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

, western

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

and

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

. It was first described by

Otto Karl Anton Schwarz Otto is a masculine German given name and a surname. It originates as an Old High German short form (variants '' Audo'', '' Odo'', '' Udo'') of Germanic names beginning in ''aud-'', an element meaning "wealth, prosperity". The name is recorded fr ...

in 1935. It has also been treated as a subspecies of ''

Quercus robur ''Quercus robur'', the pedunculate oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native plant, native to most of Europe and western Asia, and is widely cultivated in other temperate regions. It ...

'', ''Q. robur'' subsp. ''estremadurensis''. It is placed in section ''Quercus''.

Description

''Quercus estremadurensis'' is a mostly deciduous tree (when mature rarely marcescent or semievergreen) within the roburoid quercus subsection (that also comprises ''

'', ''

Quercus petraea ''Quercus petraea'', commonly known as the sessile oak, Welsh oak, Cornish oak, Irish oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of Ireland, and an un ...

'', '' Quercus hartwissiana'' and ''

Quercus canariensis ''Quercus canariensis'', the Algerian oak, Mirbeck's oak or zean oak, is an oak native to southern Portugal, Spain, Tunisia, Algeria and Morocco. Despite the scientific name, it does not occur naturally today in the Canary Islands. It is placed i ...

'') thus sharing a good number of features with its closest relative ''

'' such as bearing shortly petiolate broad and glabrous auriculated leaves, and long peduncled acorns. Also features close resemblance to other members of that subsection as happens with young tomentose sprouts and branches and fairly well elongated leaves brandishing high number of shallow lobes such as we can find in ''

'' or '' Quercus hartwissiana''. Due to its relictic status of conservation and its high propension to hybridise with any other surrounding quercus species, many characteristics are still certainly not easy to clear cut and lie under deep scientific discussion.

Distribution

Cited only in a few loci scatterly placed all over the southwestern district of the Iberian peninsula where the species might have survived the increasing process of aridification that took place in the mediterranean basin after the slow retreat of glacial conditions during last glaciation and suffering the effects of a

bottleneck Bottleneck may refer to: * the narrowed portion (neck) of a bottle Science and technology * Bottleneck (engineering), where the performance of an entire system is limited by a single component * Bottleneck (network), in a communication network * ...

phenomenon that clearly did not allow the populations to counteract and recover lost environments. Thus the cited locations for the species only contain one to five individuals but the occurrence is nevertheless not to be overlooked, occurring from Ourense in southern Galicia to northern Morocco in no less than one hundred stands, most of them appearing in the central part of Portugal both near the coast and in the mountainous interior. Over the border with Spain it has been found in Extremadura and west Andalusia, with its easternmost stand in the mountain range of Siruela, Badajoz.

References

{{Taxonbar, from1=Q55942694, from2= estremadurensis Flora of Morocco Flora of Portugal Flora of Spain Plants described in 1935