The Meta-Encyclopedia

Oak

2 of the 6 encyclopedias on this shelf carry an entry for Oak. Both are reproduced below, so you can see where they agree and where they differ.

Aiton's Encyclopedia (1910)

a genus of cupbearing trees, rarely shrubs, of the north temperate zone and the countries of the tropics. There are over 200 species. The cup of the acorn is composed of numerous reduced leaves or bracts. The halyes of the acorn are seed leaves. The acorn is an article of food for man and beast. Acorns and beechnuts are together called mast. Mast is a favorite food of the bear and razor-backed hog. The Indian of southwest California and Mexico collects acorns for food. The peasants of Italy make a black bread out of acorns. In France, prior to the French Revolution , the peasants in many sections were reduced to a diet of acorn bread. Among the oaks are the cork oak, whose bark is used for corks, and the black oak, whose galls make good ink. The live oak, frequently laden with moss, bears evergreen leaves, and is best of all for shipbuilding. The bur oak is also called the mossy-cup oak by children. The white oak is the noblest oak of all. It is a handsome tree in summer when in full foliage. Its acorns are a never ending source of pleasure in autumn. It stands like a stout old giant in winter, and "when the white oak's leaves are as large as a squirrel's ear, it is time to plant corn." The elm for grace and beauty, but the old oak for qualities that endure. "Hearts of oak," "walls of oak," "strong as an oak," "stand like an oak," "the brave old oak," are expressions that show the estimate in which the oak is held. If the Anglo-Saxon people were to toast any tree it would be with the poet Chorley: Then here's to the oak, the brave old oak, Who stands in his pride alone! And still flourish he a hale old tree When a hundred years are gone!

Collier's New Encyclopedia (1921)

K, any species of the genus Quercus and specifically Q. robur, the common British oak. It is sometimes 60 to 100 feet high, with a girth of 70 feet. There are two varieties-sessiliflora, with sessile, and pedunculata, with pedunculated flowers; the latter is the most common in natural woods. Its timber is whitish and hard, that of the other reddish and brittle. The acorns are sometimes used to feed swine. The bark is employed in tanning, and as a coarse kind of febrifuge. Oak sawdust is an ingredient in dyeing a fustian-color, also drab and brown. The decaying leaves produce heat by fermentation. Also the genus Quercus; or a species or genera more or less resembling the oak; as, the Australian Casuarina.

What Has Changed in the Last Century

The trees themselves are much as Aiton's described them in 1910, but the botany and the threats have moved on. Collier's 1921 treats sessiliflora and pedunculata as two varieties of one British oak; they are now recognised as separate species, Quercus petraea (sessile oak) and Q. robur (pedunculate oak), and the genus is reckoned at roughly 400 to 500 species rather than "over 200." The gravest change is disease: sudden oak death, caused by the pathogen Phytophthora ramorum and first noticed in California in the mid-1990s, has killed millions of tanoaks and coast live oaks, while oak wilt, identified in the American Midwest in the 1940s, spreads through root grafts. The live oak that Aiton's called "best of all for shipbuilding" now supplies timber only for the repair of the USS Constitution, and acorn bread of the sort eaten by French and Italian peasants survives as a curiosity rather than a famine food.

Written for this edition, 2026.