''Ostrya'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of eight to 10 small

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 leaves, usually in the autumn; to the shedding of petals, ...

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, including only woody plants with secondary growth, plants that are ...

s belonging to the birch family Betulaceae. Common names include hop-hornbeam and hophornbeam. It may also be called

ironwood Ironwood is a common name for many woods or plants that have a reputation for hardness, or specifically a wood density that is heavier than water (approximately 1000 kg/m3, or 62 pounds per cubic foot), although usage of the name ironwood in ...

, a name shared with a number of other plants. The genus is native in southern

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, southwest and eastern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

, and

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north ...

and

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

.Kew World Checklist of Selected Plant Families
/ref> They have a conical or irregular crown and a scaly, rough bark. They have alternate and double-toothed

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' cont ...

-like

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

3–10 cm long. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanis ...

s are produced in spring, with male

catkins A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in '' Salix''). They contain many, usually unisexual flowers, arrang ...

5–10 cm long and female aments 2–5 cm long. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

form in pendulous clusters 3–8 cm long with 6–20

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s; each seed is a small nut 2–4 mm long, fully enclosed in a bladder-like involucre. The

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

is very hard and heavy. The genus name ''Ostrya'' is derived from the Greek word (), which may be related to () "shell (of an animal)". Regarded as a weed tree by some foresters, this hard and stable wood was historically used to fashion plane soles. ''Ostrya'' species are used as food plants by the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e of some

Lepidoptera Lepidoptera ( ) is an order of insects that includes butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 percent of the total described speci ...

species, including

winter moth :''In North America, "winter moth" usually denotes the invasive species ''Operophtera brumata'', but may also mean refer to a native species, ''Erannis tiliaria'' (linden looper) or '' Operophtera bruceata'' (bruce spanworm).'' The winter moth (' ...

, walnut sphinx, and '' Coleophora ostryae''.

Species

''Ostrya'' has the following species: # ''

Ostrya carpinifolia ''Ostrya carpinifolia'', the European hop-hornbeam, is a tree in the family Betulaceae. It is the only species of the genus ''Ostrya'' that is native to Europe. The specific epithet ''carpinifolia'' means "hornbeam-leaved", from , the Latin word ...

'' Scop. – European hop-hornbeam - Mediterranean region of southern Europe, Middle-east,

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus lie ...

, Caucasus # '' Ostrya chisosensis'' Correll – Chisos hophornbeam, Big Bend hophornbeam - endemic to

Big Bend National Park Big Bend National Park is an American national park located in West Texas, bordering Mexico. The park has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, and was named after ...

in Texas # '' Ostrya japonica'' Sarg. – Japanese hophornbeam -

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

, Korea, northern China # ''

Ostrya knowltonii ''Ostrya knowltonii'' is a species of tree known by the common names Knowlton's hophornbeam, western hophornbeam, woolly hophornbeam, and wolf hophornbeam. It is also one of many trees called ironwood. It is native to Utah, Arizona, New Mexico, ...

'' Coville – Knowlton hophornbeam, western hophornbeam, wolf hophornbeam -

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

# '' Ostrya multinervis'' Rehd. – Central Chinese hop-hornbeam - central China # '' Ostrya rehderiana'' Chun – Zhejiang hop-hornbeam -

Zhejiang Province Zhejiang ( or , ; , also romanized as Chekiang) is an eastern, coastal province of the People's Republic of China. Its capital and largest city is Hangzhou, and other notable cities include Ningbo and Wenzhou. Zhejiang is bordered by Jiang ...

in China #'' Ostrya trichocarpa'' D.Fang & Y.S.Wang – Guangxi Province in China # ''

Ostrya virginiana ''Ostrya virginiana'', the American hophornbeam, is a species of '' Ostrya'' native to eastern North America, from Nova Scotia west to southern Manitoba and eastern Wyoming, southeast to northern Florida and southwest to eastern Texas. Population ...

'' (Mill.) K. Koch – eastern hophornbeam, American hophornbeam, ironwood - eastern US, eastern Canada, Mexico,

Guatemala Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by Hon ...

El Salvador El Salvador (; , meaning " The Saviour"), officially the Republic of El Salvador ( es, República de El Salvador), is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south ...

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. The republic of Honduras is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Oce ...

# '' Ostrya yunnanensis'' W.K.Hu – Yunnan hop-hornbeam -

Yunnan Province Yunnan , () is a landlocked province in the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is Kunming. The province borders the ...

in China # †'' Ostrya oregoniana'' (fossil) # †'' Ostrya scholzii'' (fossil)

Fossil record

†''Ostrya scholzii'' fossil seeds of the

Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

stage,

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but t ...

, are known from the Oberleichtersbach Formation in the

Rhön Mountains The Rhön Mountains () are a group of low mountains (or '' Mittelgebirge'') in central Germany, located around the border area where the states of Hesse, Bavaria and Thuringia come together. These mountains, which are at the extreme southeast end ...

, central

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

.The floral change in the tertiary of the Rhön mountains (Germany) by Dieter Hans Mai - Acta Paleobotanica 47(1): 135-143, 2007.

References

* Rushforth, K. (1985). "Ostrya". ''The Plantsman'' 7: 208-212.
Flora of China: ''Ostrya''

Flora Europaea: ''Ostrya''

External links

* {{Taxonbar, from=Q605290 Fagales genera