Poison oak
Oak Oak ([=o]k), n. [OE. oke, ok, ak, AS. [=a]c; akin to D. eik, G. eiche, OHG. eih, Icel. eik, Sw. ek, Dan. eeg.] [1913 Webster] 1. (Bot.) Any tree or shrub of the genus {Quercus}. The oaks have alternate leaves, often variously lobed, and staminate flowers in catkins. The fruit is a smooth nut, called an {acorn}, which is more or less inclosed in a scaly involucre called the cup or cupule. There are now recognized about three hundred species, of which nearly fifty occur in the United States, the rest in Europe, Asia, and the other parts of North America, a very few barely reaching the northern parts of South America and Africa. Many of the oaks form forest trees of grand proportions and live many centuries. The wood is usually hard and tough, and provided with conspicuous medullary rays, forming the silver grain. [1913 Webster]

2. The strong wood or timber of the oak. [1913 Webster]

Note: Among the true oaks in America are:

{Barren oak}, or

{Black-jack}, {Quercus nigra}.

{Basket oak}, {Quercus Michauxii}.

{Black oak}, {Quercus tinctoria}; -- called also {yellow oak} or {quercitron oak}.

{Bur oak} (see under {Bur}.), {Quercus macrocarpa}; -- called also {over-cup} or {mossy-cup oak}.

{Chestnut oak}, {Quercus Prinus} and {Quercus densiflora}.

{Chinquapin oak} (see under {Chinquapin}), {Quercus prinoides}.

{Coast live oak}, {Quercus agrifolia}, of California; -- also called {enceno}.

{Live oak} (see under {Live}), {Quercus virens}, the best of all for shipbuilding; also, {Quercus Chrysolepis}, of California.

{Pin oak}. Same as {Swamp oak}.

{Post oak}, {Quercus obtusifolia}.

{Red oak}, {Quercus rubra}.

{Scarlet oak}, {Quercus coccinea}.

{Scrub oak}, {Quercus ilicifolia}, {Quercus undulata}, etc.

{Shingle oak}, {Quercus imbricaria}.

{Spanish oak}, {Quercus falcata}.

{Swamp Spanish oak}, or

{Pin oak}, {Quercus palustris}.

{Swamp white oak}, {Quercus bicolor}.

{Water oak}, {Quercus aquatica}.

{Water white oak}, {Quercus lyrata}.

{Willow oak}, {Quercus Phellos}. [1913 Webster] Among the true oaks in Europe are:

{Bitter oak}, or

{Turkey oak}, {Quercus Cerris} (see {Cerris}).

{Cork oak}, {Quercus Suber}.

{English white oak}, {Quercus Robur}.

{Evergreen oak},

{Holly oak}, or

{Holm oak}, {Quercus Ilex}.

{Kermes oak}, {Quercus coccifera}.

{Nutgall oak}, {Quercus infectoria}. [1913 Webster]

Note: Among plants called oak, but not of the genus {Quercus}, are:

{African oak}, a valuable timber tree ({Oldfieldia Africana}).

{Australian oak} or {She oak}, any tree of the genus {Casuarina} (see {Casuarina}).

{Indian oak}, the teak tree (see {Teak}).

{Jerusalem oak}. See under {Jerusalem}.

{New Zealand oak}, a sapindaceous tree ({Alectryon excelsum}).

{Poison oak}, a shrub once not distinguished from poison ivy, but now restricted to {Rhus toxicodendron} or {Rhus diversiloba}.

{Silky oak} or {Silk-bark oak}, an Australian tree ({Grevillea robusta}). [1913 Webster]

{Green oak}, oak wood colored green by the growth of the mycelium of certain fungi.

{Oak apple}, a large, smooth, round gall produced on the leaves of the American red oak by a gallfly ({Cynips confluens}). It is green and pulpy when young.

{Oak beauty} (Zo["o]l.), a British geometrid moth ({Biston prodromaria}) whose larva feeds on the oak.

{Oak gall}, a gall found on the oak. See 2d {Gall}.

{Oak leather} (Bot.), the mycelium of a fungus which forms leatherlike patches in the fissures of oak wood.

{Oak pruner}. (Zo["o]l.) See {Pruner}, the insect.

{Oak spangle}, a kind of gall produced on the oak by the insect {Diplolepis lenticularis}.

{Oak wart}, a wartlike gall on the twigs of an oak.

{The Oaks}, one of the three great annual English horse races (the Derby and St. Leger being the others). It was instituted in 1779 by the Earl of Derby, and so called from his estate.

{To sport one's oak}, to be ``not at home to visitors,'' signified by closing the outer (oaken) door of one's rooms. [Cant, Eng. Univ.] [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Poison oak — is a form of "contact dermatitis" or inflammation of the skin resulting from chemicals produced from the poison oak plant contacting the skin. The chemicals cause an immune reaction producing redness, itching and blistering of the skin …   Medical dictionary

  • Poison oak — Poison Poi son, n. [F. poison, in Old French also, a potion, fr. L. potio a drink, draught, potion, a poisonous draught, fr. potare to drink. See {Potable}, and cf. {Potion}.] 1. Any agent which, when introduced into the animal organism, is… …   The Collaborative International Dictionary of English

  • poison oak — Poison Poi son, n. [F. poison, in Old French also, a potion, fr. L. potio a drink, draught, potion, a poisonous draught, fr. potare to drink. See {Potable}, and cf. {Potion}.] 1. Any agent which, when introduced into the animal organism, is… …   The Collaborative International Dictionary of English

  • poison oak — ☆ poison oak n. poison sumac or any of various poison ivy plants (esp. Rhus toxicodendron and R. diversiloba) …   English World dictionary

  • poison oak — n [U] a North American plant with leaves similar to an ↑oak tree s, that makes your skin hurt and ↑itch if you touch it …   Dictionary of contemporary English

  • poison oak — noun uncount a plant of the western U.S. that makes your skin red and painful if you touch it …   Usage of the words and phrases in modern English

  • poison oak — noun 1. dermatitis resulting from contact with a poison oak plant • Hypernyms: ↑Rhus dermatitis 2. climbing plant common in eastern and central United States with ternate leaves and greenish flowers followed by white berries; yields an irritating …   Useful english dictionary

  • poison oak — either of two shrubs, Rhus toxicodendron, of the eastern U.S., or R. diversiloba, of the Pacific coast of North America, resembling poison ivy and causing severe dermatitis when touched by persons sensitive to them. Also called poison ivy. [1735… …   Universalium

  • Poison oak — The name Poison oak refers to various species of the genus Toxicodendron that grow in North America:* Western Poison oak ( Toxicodendron diversilobum or Rhus diversiloba ), found only on the Pacific Coast of North America, ranging from southern… …   Wikipedia

  • poison oak — poi′son oak′ n. pln either of two North American shrubs of the cashew family, Rhus toxicodendron, of the eastern U.S., or R. diversiloba, of the Pacific coastal area, with leaves resembling those of poison ivy: may cause allergic dermatitis when… …   From formal English to slang

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