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Quercus pubescens, somewhere in Istria. |
Not pictured above or listed below:
- Quercus pseudosuber G. Santi / Quercus crenata Lam. - Sea bark oak / Cork oak / Lucombe oak - Cerro sughera / Quercia di falso - [semi-evergreen, very rare for Istria and Italy - may be considered part of Section Quercus cerris L.]
The term oak can be used as part of the common name of any of several hundred species of trees and shrubs in the genus Quercus, and some related genera, notably Lithocarpus (Tanbark oaks). (Other trees that are sometimes called oak are Casuarina, Grevillea, and Rhus, as is also a weedy herb known as Jerusalem oak: Chenopodium Botrys.). The genus is native to the northern hemisphere, and includes deciduous and evergreen species extending from cold latitudes to tropical Asia and the Americas. The fruits of oaks are called acorns. The "live oaks" (oaks with evergreen leaves) are not a distinct group, instead with their members scattered among the sections below.
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Black oak
group {left) |
The genus comprises the finest hardwood timber trees in the temperate world, and it also furnishes many species of great beauty for planting on lawns, parks, street, or for the home woodlot. All oaks, as here restricted, belong to the genus Quercus (kwer'kus) of the family Fagaceae. The genus comprises perhaps 200 species, nearly all from the north temperate zone, a few outliers in mountainous regions in the tropics. By far the larger number are evergreen, especially the Asiatic species, and the group as a whole just misses being evergreen in N.A., where many species have leaves, usually withered, that persist over most of the winter. In the list below, however, only those whose leaves stay green through the winter are designated as evergreen. All others are deciduous.
Leaves alternate, stalked, variously lobed, toothed or divided in most species, but unlobed and without teeth in a few. In those that are lobed or toothed, about a third have the lobes or teeth bristle-pointed (the black oak group) but the rest have no bristles on the lobes or teeth (the white oak group); but this character does not hold in the evergreen species. Flowers unisexual, but on the same tree, the male in drooping catkins, the female in short spikes, or solitary, both without petals. Most of them flower very early in the spring. Fruit a true nut (the acorn) set in a cup-like involucre, which may surround the nut only at the base, or partly or completely cover it; the cup sometimes fringed. In some species the acorns are edible and others furnish large quantities of food for hogs. (Quercus is the classical Latin name for the oak.)
Classification:
The genus is divided into two subgenera and a number of sections:
Subgenus Quercus: Typical oaks
Widespread; lobed leaves, acorns not tightly clustered, with scales on acorn cup arranged in spirals.
- Quercus (synonyms Lepidobalanus and Leucobalanus), the white oaks of Europe, Asia and North America. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless. Leaves mostly lack a bristle on lobe tips, which are usually rounded.
- Mesobalanus, the Hungarian oak and its relatives of Europe and Asia. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. Quercus and sometimes included in it).
- Cerris, the Turkey oak and its relatives of Europe and Asia. Styles long; acorns mature in 18 months, very bitter. Cup of the acorn is roughish and covering about 1-2 of the nut, inside of acorn the shell is hairless. Leaves typically oblongish, 3-5 in. long, with 4-9 pairs of sharp-pointed lobes with bristles at the lobe tip instead of teeth. Grows up to 100 ft. high, deciduous.
- Protobalanus, the intermediate oaks (Canyon live oak and its relatives), in southwest USA and northwest Mexico. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
- Lobatae (synonym Erythrobalanus), the red oaks of North, Central and northern South America. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly. Leaves typically have sharp lobe tips, with bristles at the lobe tip.
[Note: Species with evergreen foliages are tagged #. Note that the change from deciduous to evergreen character (or vice-versa) has evolved on numerous occasions in Quercus, and does not necessarily indicate that the species concerned are closely related.]
1. Quercus
The white oaks (synonym sect. Lepidobalanus and Leucobalanus). Europe, Asia, north Africa, North America. Styles short; acorns mature in 6 months, sweet or slightly bitter, inside of acorn shell hairless.
- Quercus alba - White oak (Any of numerous Old World and American oaks having 6 to 8 stamens in each floret, acorns that mature in one year and leaf veins that never extend beyond the margin of the leaf) - eastern North America
- Quercus aliena - Oriental white oak - eastern Asia
- Quercus arizonica - Arizona white oak # - southwestern North America
- Quercus austrina - Bluff oak- southeastern North America
- Quercus bicolor - Swamp white oak (Large flaky-barked deciduous oak of the eastern United States with leaves having fewer lobes than other white oaks; yields heavy strong wood used in construction; thrives in wet soil) - eastern & midwestern North America
- Quercus boyntonii - Boynton's post oak - south central North America
- Quercus chapmannii - Chapmann oak - southeastern North America
- Quercus depressipes - - Texas
- Quercus douglasii - Blue oak (additional info and facts about Blue oak) - southwestern North America
- Quercus emoryi - Emory oak (additional info and facts about Emory oak) # - southwestern North America
- Quercus faginea - Portuguese oak - southwestern Europe
- Quercus fusiformis - Texas live oak (additional info and facts about Texas live oak) - south central North America
- Quercus gambelii - Gambel oak - southwestern North America
- Quercus garryana - Oregon white oak (Small deciduous tree of western North America with crooked branches and pale gray bark) - western North America
- Quercus geminata - Sand live oak # - southeastern North America
- Quercus grisea - Gray oak - south central North America
- Quercus havardii - Sand shinnery oak, Shin oak - south central North America
- Quercus hinckley - - Texas (The second largest state; located in southwestern United States on the Gulf of Mexico)
- Quercus ilex - Holm oak (Evergreen oak of southern Europe having leaves somewhat resembling those of holly; yields a hard wood) # - southern Europe, northwestern Africa
- Quercus intricata - - Texas
- Quercus laceyi - Lacey oak - south central North America
- Quercus lanata - Woolly-leaved oak # - Himalaya
- Quercus leucotrichophora - Himalayan oak # - Himalaya
- Quercus lobata - Valley oak or California white oak - southwestern North America
- Quercus lyrata - Overcup oak - eastern North America
- Quercus macrocarpa - Bur oak (Medium to large deciduous oak of central and eastern North America with ovoid acorns deeply immersed in large fringed cups; yields tough close-grained wood) - eastern & central North America
- Quercus mohriana - Mohr oak - southwestern North America
- Quercus michauxii - Swamp chestnut oak (Medium to large deciduous tree of moist areas of southeastern United States similar to the basket oak) - eastern North America
- Quercus minima - Dwarf live oak # - southeastern North America
- Quercus mongolica - Mongolian oak - eastern Asia
- Quercus montana - Chestnut oak (An oak having leaves resembling those of chestnut trees) - eastern North America (syn. Q. prinus)
- Quercus muhlenbergii - Chinkapin oak (Medium-sized deciduous tree of the eastern United States that yields a strong durable wood) - eastern North America
- Quercus oblongifolia - Mexican blue oak # - western North America
- Quercus oglethorpensis - Oglethorpe oak - southeastern North America
- Quercus petraea - Sessile oak (additional info and facts about Sessile oak) - Europe
- Quercus polymorpha - Monterrey oak# - Mexico (A Republic in southern North America; became independent from Spain in 1810) & extreme S. Texas
- Quercus prinoides - Dwarf chinkapin oak - eastern North America
- Quercus pubescens - Downy oak (additional info and facts about Downy oak) - Europe
- Quercus pungens - Sandpaper oak # - south central North America
- Quercus robur - Pedunculate oak (Medium to large deciduous European oak having smooth leaves with rounded lobes; yields hard strong light-colored wood) , English oak - Europe, West Asia
- Quercus rugosa - Netleaf oak# - Mexico
- Quercus stellata - Post oak (Small deciduous tree of eastern and central United States having dark green lyrate pinnatifid leaves and tough moisture-resistant wood used especially for fence posts) - eastern North America
- Quercus toumeyi - Toumey Oak - Extreme SW. New Mexico
- Quercus turbinella - Scrub live oak # - southwestern North America
- Quercus vaseyana - Vasey oak - southwestern North America
- Quercus virginiana - Southern live oak (Medium-sized evergreen native to eastern North America to the east coast of Mexico; often cultivated as shade tree for it wide-spreading crown; extremely hard tough durable wood once used in shipbuilding) # - southeastern North America
2. Mesobalanus
The Hungarian oak and its relatives. Europe, Asia, north Africa. Styles long; acorns mature in 6 months, bitter, inside of acorn shell hairless (closely related to sect. Quercus and sometimes included in it).
- Quercus dentata - Daimyo oak - eastern Asia
- Quercus frainetto - Hungarian oak (additional info and facts about Hungarian oak) - southeastern Europe
- Quercus macranthera - Caucasian oak - western Asia
- Quercus pontica - Armenian oak - western Asia
- Quercus pyrenaica - Pyreneean oak - southwestern Europe
- Quercus vulcanica - Kasnak oak - southwestern Asia
3. Cerris
The Turkey oak and its relatives. Europe, Asia, north Africa. Styles long; acorns mature in 18 months, very bitter, inside of acorn shell hairless or slightly hairy.
- Quercus acutissima - Sawtooth oak - eastern Asia
- Quercus calliprinos - Palestine oak # - southwestern Asia
- Quercus cerris - Turkey oak (Large deciduous tree of central and southern Europe and Asia Minor having oblong-lanceolate leaves with spiked lobes) - southern Europe, southwestern Asia
- Quercus coccifera - Kermes oak # - southern Europe
- Quercus libani - Lebanon oak - southwestern Asia
- Quercus macrolepis - Vallonea oak - southwestern Asia
- Quercus semecarpifolia - Himalayan oak # - southern Asia
- Quercus suber - Cork oak (Medium-sized evergreen oak of southern Europe and northern Africa having thick corky bark that is periodically stripped to yield commercial cork) # - southwestern Europe, northwestern Africa
- Quercus trojana - Macedonian oak (additional info and facts about Macedonian oak) - southeastern Europe
- Quercus variabilis - Chinese cork oak - eastern Asia
4. Protobalanus
The intermediate oaks (the Canyon live oak and its relatives). Southwest USA & northwest Mexico. Styles short, acorns mature in 18 months, very bitter, inside of acorn shell woolly.
- Quercus cedrosensis - Cedros Island oak # - Baja California
- Quercus chrysolepis - Canyon live oak # - southwestern North America
- Quercus palmeri - Palmer oak # - southwestern North America
- Quercus tomentella - Island oak (additional info and facts about Island oak) # - southwestern North America
- Quercus vaccinifolia - Huckleberry oak # - southwestern North America
5. Lobatae
The red oaks (synonym sect. Erythrobalanus). North, Central & South America. Styles long, acorns mature in 18 months, very bitter, inside of acorn shell woolly.
- Quercus acerifolia - # - south central North America
- Quercus agrifolia - Coast live oak (Highly variable often shrubby evergreen oak of coastal zone of western North America having small thick usually spiny-toothed dark-green leaves) # - southwestern North America
- Quercus arkansana - Arkansas oak - southeastern North America
- Quercus buckleyi - Texas shumard oak - southwestern North America
- Quercus canbyi - Canby oak # - Mexico
- Quercus coccinea - Scarlet oak - eastern North America
- Quercus ellipsoidalis - Northern pin oak - eastern North America
- Quercus emoryi - Emory oak (additional info and facts about Emory oak) - southwestern North America
- Quercus falcata - Southern red oak (Large round-topped deciduous tree with spreading branches having narrow falcate leaves with deeply sinuate lobes and wood similar to that of northern red oaks; New Jersey to Illinois and southward), or Spanish oak - southeastern North America
- Quercus gravesii - Chisos red oak - Mexico, southwestern North America (Texas)
- Quercus graciliformis - # - Extreme SW North America
- Quercus georgiana - Georgia oak (additional info and facts about Georgia oak) - southeastern North America
- Quercus humboldtii - South American Oak # - northern South America
- Quercus hypoleucoides - Silverleaf oak # - southwestern North America
- Quercus ilicifolia - Bear oak - eastern North America
- Quercus imbricaria - Shingle oak - eastern North America
- Quercus incana - Bluejack oak - southwestern North America
- Quercus inopina - # - southeastern North America
- Quercus kelloggii - California black oak (Large deciduous tree of the Pacific coast having deeply parted bristle-tipped leaves) - western North America
- Quercus laevis - American turkey oak (Small slow-growing deciduous shrubby tree of dry sandy barrens of southeastern United States having leaves with bristle-tipped lobes resembling turkey's toes) - southeastern North America
- Quercus laurifolia - Laurel oak (Large nearly semi-evergreen oak of southeastern United States; thrives in damp soil) # - southeastern North America
- Quercus marilandica - Blackjack oak (A common scrubby deciduous tree of central and southeastern United States having dark bark and broad 3-lobed (club-shaped) leaves; tends to form dense thickets) - eastern North America
- Quercus myrtifolia - Myrtle oak - southeastern North America
- Quercus nigra - Water oak # - eastern North America
- Quercus palustris - Pin oak (Fast-growing medium to large pyramidal deciduous tree of northeastern United States and southeastern Canada having deeply pinnatifid leaves that turn bright red in autumn; thrives in damp soil) - eastern North America
- Quercus phellos - Willow oak (Medium to large deciduous oak of the eastern United States having long lanceolate leaves and soft strong wood) - eastern North America
- Quercus polymorpha - Coahuila oak # - Mexico
- Quercus pumila - Runner oak - southeastern North America
- Quercus rhysophylla - Loquat-leaf oak # - Mexico
- Quercus rubra - Northern red oak (Large symmetrical deciduous tree with rounded crown widely distributed in eastern North America; has large leaves with triangular spiny tipped lobes and coarse-grained wood less durable than that of white oaks) - eastern North America
- Quercus shumardii - Shumard oak - eastern North America
- Quercus tardifolia - Lateleaf oak - Extreme S.Texas
- Quercus texana - Nuttall's oak - south central North America
- Quercus velutina - Black oak (Medium to large deciduous timber tree of the eastern United States and southeastern Canada having dark outer bark and yellow inner bark used for tanning; broad 5-lobed leaves are bristle-tipped) - eastern North America
- Quercus wislizenii - Interior live oak (Medium-small shrubby evergreen tree of western North America similar to the coast live oak but occurring chiefly in foothills of mountain ranges removed from the coast; an important part of the chaparral) # - southwestern North America
Subgenus Cyclobalanopsis: Cluster-acorn oaks
A large group of evergreen oaks in east Asia with clustered acorns and the scales on the acorn cups in distinct concrescent rings (see photo, right); often treated as a separate genus Cyclobalanopsis.
Section Cyclobalanopsis
- Quercus acuta - Japanese evergreen oak # - eastern Asia
- Quercus glauca - Glaucous-leaf oak # - southeastern Asia
- Quercus kerrii - Kerr's oak # - southeastern Asia
- Quercus lamellosa - # - Himalaya
- Quercus lineata - # - southeastern Asia
- Quercus myrsinifolia - Bamboo-leaf oak # - eastern Asia
- Quercus oxyodon - # - Assam (State in northeastern India), Myanmar (A mountainous republic in southeastern Asia on the Bay of Bengal)
- Quercus dilatata - # - Himalaya (additional info and facts about Himalaya) (not sure what subgenus)
External links
Sources:
- Norman Taylor, Taylor's Encyclopedia of Gardening, 4th Edition, Houghton Mifflin Co. (Boston, 1961)
- http://www.absoluteastronomy.com/encyclopedia/l/li/list_of_quercus_species.htm
- Claudio Pericin, "Frutti selvatici 2 - Piccole delizie di bosco", Jurina i Franina, Rivista di varia cultura istriana, No. 59, inverno 1995, Libar od Grozda - Pola, p. 62-70.
- Sketches - http://www.bdp.it/park/percorsi/sentiero4/querce.htm
This page compliments of Marisa Ciceran
Created: Thursday,
December 29, 2005; Last updated:
Sunday, March 02, 2008
Copyright © 1998
IstriaNet.org, USA