Page:The American Cyclopædia (1879) Volume XII.djvu/572

558 OAK OAK APPLE the early historians. In England it is used in ornamental planting and for screens ; it is not hardy in our northern states. The acorns of several Californian species furnish a large share Valonia Oak (Quercus segilops). of the winter food of the Indians of the west- ern coast. They are powdered in a mortar, and the meal, after washing it to remove the bitterness, is made into cakes or mush. An evergreen species, Q. ballota, abundant in Al- geria and Morocco, has large nuts which are eaten raw or roasted. The acorns of the Gra- rnont oak (Q. Gramuntia) of Spain, when in perfection, are regarded as even superior to chestnuts, and are much eaten. Besides the use of the bark in tanning (see LEATHER), a secondary one is of some importance in horti- culture ; a mass of the spent tan bark gradual- ly ferments and gives off a mild heat, which, though more gentle than that from manure, is long continued and especially adapted to some plants, particularly the pineapple. In the va- lonia oak (Q. c&gilops) of the Grecian islands and throughout Greece, the tannin is so abun- dantly secreted in the acorn cups that these form an article of commerce under the name of valonia; the tree is large, with foliage much like that of our chestnut oaks, and large acorns, the cups of which are about 2 in. across, hemi- spherical, and clothed with large reflexed woody scales. Two varieties are also known in com- merce : camata, which is the half -grown acorns dried in their cups, and camatina, which is the undeveloped acorns gathered soon after flow- ering when about the size of large peas ; these last are much richer in tannin than the other two. Besides the yellow dye of the quercitron oak, a crimson one is furnished by Q. coccifera, found in the Levant ; its leaves are much in- fested by a scale insect, a species of coccus, which when it has completed its growth has every appearance of a berry, and is known as kermes. (See COCHINEAL.) The oak manna of Kurdistan, usually ascribed to Q. mannifera, is, according to Haussknecht, afforded by Q. vallonea and Q. Persica ; the twigs are visited by myriads of a small white coccus, and from the punctures made by these exudes a saccha- rine fluid. which solidifies in small grains ; this is collected by the wandering tribes, who use it as a substitute for sugar. Oaks form very long perpendicular tap roots, and in cul- tivation when the plants are a year old they should be transplanted, and at the same time the tap root be shortened ; by frequent trans- planting thereafter, trees may be obtained with a good share of small roots, and such may be removed without difficulty. In planting for timber or for ornament, except in streets, the surer way is to put in several acorns where the trees are to stand, and when the plants are two or three years old remove all but one. Al- though so hardy and robust when old, the oak is exceedingly tender during its first few years ; and in England it is customary to provide "nurse trees," which shade and protect the oaks until they become thoroughly established. There are many fine oaks in Japan and northern China, as well as in the mountainous parts of Mexico and the Himalayas. OAK APPLE, the popular name applied to certain large excrescences or galls found upon the leaf, stems, or tender twigs of different oaks, produced by the action of insects. The oak apple of Europe, to which the term more par- ticularly applies, is an object familiar to every English school boy, and is produced by cynips terminalis. It is of the size of an ordinary apple, and is found quite commonly about Easter time on the tender shoots and twigs of the common European oak (quercus rdbur). At this time it presents the appearance of an ordinary codling that has been roasted, being of a pale, dingy buff color, of spongy consis- tence, and having an irregular and wrinkled surface. The American oak apple, which is Gall Fly magnified. The lines below show the natural length of body and wings. its analogue, is produced on the leaf stem of the black oak (Q. tinctoria) by cynips q. spon- gifica. In both these instances the gall is pro- duced in the same manner as the well known gall nut of commerce. (See GALLS.) With her ovipositor, admirably adapted to the purpose, the female pierces the plant tissues, and there- in consigns an egg, together with a small quan- tity of a peculiar poisonous fluid. Under the influence of this fluid the gall rapidly devel- ops, and is generally fully formed before the egg hatches. The egg is whitish in color and soft. It invariably swells more or less by en- dosmosis of the surrounding juices, and the outer pellicle is so delicate that no shell is