Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/751

Rh OAK 693 growing in glades or other open places, huge spreading boughs, less twisted and gnarled than those of the English oak and covered with a whitish bark that gives a marked character to the tree. The leaves are large, often irregular in form, usually with a few deep lobes dilated at the end ; they are of a bright light green on the upper surface, but whitish beneath; they turn to a vio let tint in au tumn. The egg - shaped acorns are placed singly or two together onshortstalks; they are in most years sparingly pro duced, but are occasionally borne in some abundance. On rich loams and the alluvial soils of river- valleys, when well drained, FIG. 4. Q. alba pinnatifida ; one-third natural size. (From the tree attains Jlichaux, histoire des chenes de VAmerique.) a large size, often rivalling the giant oaks of Europe ; trunks of 3 or 4 feet in diameter are frequently found, and sometimes these dimensions are greatly exceeded. The wood is variable in quality and, though hard in texture, is less durable than the best oak of British growth ; the heart-wood is of a light reddish brown varying to an olive tint ; a Canadian specimen weighs 52 lb the cubic foot. In the States it is largely used in shipbuilding, for house timber, and many other purposes ; wheels and the frames of waggons and sleighs as well as casks are often made of it ; large quantities are exported to England from Canada. The young wood is very strong, flexible, and elastic ; it is split into thin strips, to be made into baskets. The large roots, often presenting a very fine grain and taking a good polish, are sought for by the cabinetmaker. The bark is inferior to that of many oaks. The acorns are sweet, and were formerly eaten by the Ked Men, but are too scantily produced in most seasons to be of much economic importance. White oaks have often been planted in England, but the trees do not grow as fast as in their native land, while the wood is inferior. According to some American authorities, the timber of Q. alba is of better quality in the southern and middle States than in Canada and New England. Q. obtusiloba, the post oak of the backwoodsman, a smaller tree with rough leaves and notched upper lobes, produces an abundance of acorns and good timber, said to be more durable than that of the white oak. The pin oak, sometimes called the &quot;over-cup &quot; oak, Q. macrocarpa, is remarkable for its large acorns, the cups bordered on the edge by a fringe of long narrow scales ; the leaves are very large, some times from 10 inches to a foot in length, with very deep lobes at the lower part, but dilated widely at the apex, and there notched. The tree is not of large growth, but its tough wood is useful for bolts and trenails ; it is sometimes called the &quot;burr-oak.&quot; The true over-cup oak, Q. lyrata, is a large tree, chiefly found on swampy land in the southern States ; the lyrate leaves are dilated at the end ; the globose acorns are nearly covered by the tuberculated cups. In the woods of Oregon, from the Columbia river southwards, an oak is found bearing some resemblance to the British oak in foliage and in its thick trunk and widely-spreading boughs, but the bark is white as in Q. alba ; it is Q. Garryana, the western oak of Nuttall. This tree acquires large dimensions, the trunk being often from 4 to 6 feet in diameter ; the wood appears to be good, but experience has scarcely tested its durability ; the acorns are produced in great quantity, and are used by the Indians as food. The red oak, Q. nibra, has thin large leaves on long petioles, the lobes very long and acute, the points almost bristly ; they are pink when they first expand in spring, but become of a bright glossy green when full-grown ; in autumn they change to the deep purple- red which gives the tree its name. Common throughout the northern and middle States and Canada, the red oak attains a large size only on good soils ; the wood is of little value, being coarse and porous, but it is largely used for cask - staves ; the bark is a valuable tanning material. A species nearly allied is the scarlet oak, Q. coccinca, often confounded with the red oak, but with larger leaves, with long lobes ending in several acute points ; they change to a brilliant scarlet with the first October frosts, giving one of the most striking Fio. 5. Q. rubra; one-fourth natural size. (From Michaux, op cit. plate xxxv.) of the various glowing tints that render the American forests so beautiful in autumn. The trunk, though often of considerable size, yields but an indifferent wood, employed for similar purposes to that of Q. rubra ; the bark is one of the best tanning materials of the country. Both these oaks grow well in British plantations, where their bright autumn foliage, though seldom so decided in tint as in their native woods, gives them a certain picturesque value. Nearly akin to these are several other forms of little but botanical interest ; not far removed is the black or dyer s oak, Q. tinctoria, a large and handsome species, with a trunk sometimes 4 feet in diameter, not uncommon in most forests east of the Mississippi, especially in somewhat upland districts. The leaves are frequently irregular in outline, the lobes rather short and blunt, widening towards the end, but with setaceous points ; the acorns are nearly globular. The wood is coarsely grained, as in all the red-oak group, but harder and more durable than that of Q. rubra, and is often employed for building and for flour-barrels and cask-staves. The bark, very dark externally, is an excellent tanning substance ; the inner layers form the quercitron of commerce, used by dyers for communicating to fabrics various tints of yellow, and, with iron salts, yielding a series of brown and drab hues ; the colouring property depends on a crystalline principle called quercitrin, of which it should contain about 8 per cent. The cut -leaved oaks are represented in eastern Asia by several species, of which Q. mongolica is widely spread over Dahouria, north China, and the adjacent countries ; one of the Chinese silkworms is said to feed on the leaves. The chestnut oaks of America represent a section distin guished by the merely serrated leaves, with parallel veins running to the end of the serratures. Q. Prinus, a beau tiful tree of large growth, and its sub species Q. castanea and Q. montana, yield timber little inferior to white oak. Q. Chinquapin or prinoides, a dwarf variety, often only a foot in height, forms dense miniature thickets on the barren uplands of Kansas and Missouri, and affords abundant sweet acorns ; the tree is called by the hunters of the plains the &quot; shin-oak.&quot; Evergreen oaks with entire leaves are represented in North America by Q. vircns, the live oak of the southern States ; more or less abundant on the Atlantic coasts of Carolina and Florida, its true home is the country around the ^ Mexican Gulf, where it rarely, grows more than 50 or 60 miles inland. The oval leaves are dark-green above, and whitish with stellate hairs beneath, the margin entire and slightly recurved. The live oak is one of the most valu able timber trees of the genus, the wood / being extremely durable, both exposed / -jL ^ ^ to air and under water; heavy and FlG c __ Q castanese f u a (^ yn ); close-grained, it is perhaps the best oi one-third natural size. (From the American oaks for shipbuilding, Kotschy, op. cit., plate xl.) and is invaluable for water-wheels and mill -work. Live oaks grow but slowly, and few large trees are left in the settled districts ; but when standing in open places the trunk sometimes attains a great size, and an old tree, with its far-spreading boughs, often clothed with the beard - like &quot; Spanish moss,&quot; has a peculiarly