''Quercus hartwissiana'', the Strandzha oak (), 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 ...

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 ...

to southeastern

Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...

, northern

Asia Minor Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...

along the

Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...

, and the

Caucasus The Caucasus () or Caucasia (), is a region spanning Eastern Europe and Western Asia. It is situated between the Black Sea and the Caspian Sea, comprising parts of Southern Russia, Georgia, Armenia, and Azerbaijan. The Caucasus Mountains, i ...

. It was described by the Finnish-born Russian botanist and entomologist

Christian von Steven Christian von Steven (; 19 January 1781 – 30 April 1863) was a Finnish-born Russian botanist and entomologist. Life Steven was of Swiss descent. At the age of 57 he married a young widow, Marie Karlovna Gartzewitsch (née Hagendorff), ...

in 1857.

Description

''Quercus hartwissiana'' is a large

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

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 ...

, reaching heights of , with umbrella-shaped crown and ascending branches. The

bark Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...

is thick, finely furrowed, almost black. The

shoot Shoot most commonly refers to: * Shoot (botany), an immature plant or portion of a plant * Shooting, the firing of projectile weapons * Photo shoot, a photography session; an event wherein a photographer takes photographs Shoot may also refer t ...

s are dark reddish-brown and bald. The

bud In botany, a bud is an undeveloped or Plant embryogenesis, embryonic Shoot (botany), shoot and normally occurs in the axil of a leaf or at the tip of a Plant stem, stem. Once formed, a bud may remain for some time in a dormancy, dormant conditi ...

s are broad, oval or almost round, long, with short burnished scales. The

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

is long. 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 long and 7 to 9 cm wide, slightly convex in the base, and have seven to ten pairs of fairly regular, short, rounded to pointed lobes. The leaf veins are all directed into the lobes of the leaf, not into the indentations between them. The top of the leaf is bright green, the underside is dull, with a dark brown shading, with fine fleece and somewhat longer reddish hairs along the leaf veins, or in the angles between them. On a petiole with a length of 2 to 7 cm, there are one to four

acorn The acorn is the nut (fruit), nut of the oaks and their close relatives (genera ''Quercus'', ''Notholithocarpus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains a seedling surrounded by two cotyledons (seedling leaves), en ...

s. Their fruits mature in the first year. The acorns are 2.5 to 3 cm long and 1.2 to 1.5 cm wide, the fruit cups measure 1.5 cm in length and 2 cm in diameter. The scales of the fruit cup are almost full to the top.

Epithet

The specific epithet ''hartwissiana'' is in honour of Russian botanist

Nicolai Anders von Hartwiss Nicolai Anhorn von Hartwiss (Николай Андерс фон, ''де'' Гартвис, ''Николай Андреевич''; was a Livonian-born, Baltic German, Russian botanist, plant explorer and plant breeder. His education at the universi ...

Distribution

''Quercus hartwissiana'' is found in the Euxine–Colchic deciduous forests ecoregion, in the

temperate broadleaf and mixed forests Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. These ...

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

along the

from the south-easternmost parts of the

Balkan Peninsula The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...

along northern

to western

. It grows in

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

and

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. In Bulgaria ''Quercus hartwissiana'' grows in

Strandzha Nature Park Strandzha Nature Park ( ''Priroden park Strandzha'', also transliterated as Stranja Nature Park) is the List of protected areas of Bulgaria, largest protected area in Bulgaria spanning a territory of in the Strandzha Mountain in the extreme sou ...

and is distributed in the dense forest ecotype and the karst or xelophilous ecotype. In

Strandzha Strandzha (, also transliterated as ''Strandja'', ; , or ) is a mountain massif in southeastern Bulgaria and East Thrace, the European part of Turkey. It is in the southeastern part of the Balkans between the plains of Thrace to the west, th ...

it grows near river valleys, especially those of

Veleka The Veleka ( , ) is a river in the very southeast of Bulgaria, as well as the very northeast of European Turkey. It is 147 km long, of which 108 km lie in Bulgaria and 25 km are in Turkey. It flows into the Black Sea at the Bulga ...

and

Rezovo Rezovo (, ) is a village and seaside resort in far southeastern Bulgaria, part of Tsarevo Municipality, Burgas Province, in the coastal Strandzha geographical region. It is situated on the Bulgaria–Turkey border. Geography The village is in S ...

. There it is mixed with ''

Carpinus betulus Hornbeams are hardwood trees in the plant genus ''Carpinus'' in the family Betulaceae. Its species occur across much of the temperateness, temperate regions of the Northern Hemisphere. Common names The common English name ''hornbeam'' derives ...

'', ''

Fagus orientalis ''Fagus orientalis'', commonly known as the Oriental beech, is a deciduous tree in the beech family Fagaceae. It is native to Eurasia, in Eastern Europe and Western Asia. Description ''Fagus orientalis'' is a large tree, capable of reaching he ...

'', ''

Torminalis glaberrima ''Torminalis'' is a genus of plants in the rose family, Rosaceae. The genus was formerly included within the genus ''Sorbus'' as the section ''Torminaria'', but the simple-leafed species traditionally classified in ''Sorbus'' are now considered ...

'', ''

Quercus pubescens ''Quercus pubescens'' (Synonym (taxonomy), synonyms ''virgiliana''), commonly known as the downy oak, pubescent oak or Italian oak, is a species of white oak (genus ''Quercus'' sect. ''Quercus'') native to southern Europe and southwest Asia. It ...

'', ''

Quercus cerris ''Quercus cerris'', the Turkey oak or Austrian oak, is an oak native to south-eastern Europe and Asia Minor. It is the type species of ''Quercus'' sect. ''Cerris'', a section of the genus characterised by shoot buds surrounded by soft bristles, ...

'', ''

Quercus frainetto ''Quercus frainetto'' (Synonym (taxonomy), synonyms ''Quercus conferta'', ''Quercus farnetto''), commonly known as the Hungarian oak, is a species of oak, native plant, native to southeastern Europe (parts of Italy, the Balkans, parts of Hungary, ...

'', ''

Carpinus orientalis ''Carpinus orientalis'', known as the Oriental hornbeam, is a species of hornbeam in the birch family Betulaceae, subfamily Coryloideae, native to southeastern Europe and Western Asia. It is quite tolerant of dry conditions, and usually occurs on ...

'' and the shrubs ''

Cistus creticus ''Cistus creticus'' (pink rock-rose, hoary rock-rose) is a species of shrubby plant in the family Cistaceae. Though it usually has pink flowers, of 4.5–5 cm diameter, this species is very variable. It is widely known as a decorative plant ...

'' and ''

Daphne pontica ''Daphne pontica'', commonly known as twin-flowered or Pontic daphne, is a species of flowering plant in the family (biology), family Thymelaeaceae, native plant, native to Bulgaria, northern Turkey and the Caucasus. It is a small evergreen shrub ...

''. In Russia it occurs in the basin of the

Mzymta River The Mzymta (; Abkhaz: Мӡы́мҭа; , ''Mezmytha'') is a river in Northwestern Caucasus, flowing through Mostovsky District and the city of Sochi ( Adlersky City District) of Krasnodar Krai, Russia. The Mzymta is the largest river in Russia ...

and in the North Caucasus. In Georgia it is known from

Abkhazia Abkhazia, officially the Republic of Abkhazia, is a List of states with limited recognition, partially recognised state in the South Caucasus, on the eastern coast of the Black Sea, at the intersection of Eastern Europe and West Asia. It cover ...

Racha-Lechkhumi and Kvemo Svaneti Racha-Lechkhumi and Kvemo Svaneti ( ka, რაჭა-ლეჩხუმი და ქვემო სვანეთი, ''Rach’a-Lechkhumi da Kvemo Svaneti'' ) is a region (mkhare) in northwestern Georgia (country), Georgia with a population o ...

Samegrelo Mingrelia or Samegrelo ( ka, სამეგრელო, tr ; ) is a historic province in the western part of Georgia, formerly known as Odishi. It is primarily inhabited by the Mingrelians, a subgroup of Georgians. Geography and climate Mingre ...

Imereti Imereti ( Georgian: იმერეთი, ) is a region of Georgia situated in the central-western part of the republic along the middle and upper reaches of the Rioni River. Imereti is the most populous region in Georgia. It consists of 11 mun ...

Guria Guria ( ka, გურია) is a region (''mkhare'') in Georgia (country), Georgia, in the western part of the country, bordered by the eastern end of the Black Sea. The region has a population of 104,338 (2023), with Ozurgeti as the regional cap ...

and

Adjara Adjara ( ka, აჭარა ''Ach’ara'' ) or Achara, officially known as the Autonomous Republic of Adjara ( ka, აჭარის ავტონომიური რესპუბლიკა ''Ach’aris Avt’onomiuri Resp’ublik’a ...

; in eastern Georgia it is now known only from

Kakheti Kakheti (; ) is a region of Georgia. Telavi is its administrative center. The region comprises eight administrative districts: Telavi, Gurjaani, Qvareli, Sagarejo, Dedoplistsqaro, Signagi, Lagodekhi and Akhmeta. Kakhetians speak the ...

. It always occurs in mixed forests along with other tree species. ''Quercus hartwissiana'' prefers warm and humid climate and grows on fresh to moist soil from the lowland to an altitude of . It is a pre-glacial relict and is considered to be the ancestor 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 ...

'' and ''

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 ...

''.

Fossil record

Fossils of ''Quercus hartwissiana'' have been described from the

fossil flora of Kızılcahamam district This fossil flora in Turkey stems from at least six Pliocene deposits in Güvem and Beşkonak villages, north of Ankara, north of Kızılcahamam and south of the Black Sea coast. They are to above sea level, extending north-south and eas ...

, which is of early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58List of Quercus species The genus ''Quercus'' contains about 500 known species, plus about 180 hybrids between them. The genus, as is the case with many large genera, is divided into subgenera and sections. Traditionally, the genus ''Quercus'' was divided into the tw ...

* Euxine-Colchic deciduous forests *

Citations

References

* * *

External links

* {{Taxonbar, from=Q4169047 hartwissiana Flora of Bulgaria Flora of Georgia (country) Plants described in 1857 Trees of Europe Trees of Turkey