Page:The American Cyclopædia (1879) Volume XII.djvu/567

 OAK 553 for staves, and is used for knees in ship build- ing. The burr oak (Q. macrocarpa), closely re- lated to the two preceding species, is in some localities known as the over-cup, and in others Burr or Over-cup Oak (Quercus macrocarpa). as the mossy-cup white oak ; it is of medium height with irregular branches ; its large leaves are obovate in general outline, deeply lobed be- low the middle, often nearly to the midrib, and broader and more entire to ward the apex, smooth and dark green above, and downy or light-col- ored beneath. The acorn is broadly ovate, 1 to H in. long, and wholly or partly immersed in its cup, which is thick and woody, and very conspicuous, not only on account of its size, but from being covered with prominent scales, the upper of which terminate in leafy points, to form a mossy fringe to the edge of the cup ; the relative size of the acorn to the cup varies greatly. The burr oak is much more abun- dant in the western than in the Atlantic states, and in richer soils than the white and post oaks. When it has room to develop it forms a handsome tree ; and as it grows more rapidly than most other oaks, it is well adapted to or- namental planting, while the value of its tim- ber, being nearly equal to that of white oak, renders it desirable for forest planting. As its wood is preferred for making the treenails or wooden pins used in ship building, this spe- cies is in some parts of New England called pin oak, a name which properly belongs to another species. The southern over-cup oak (Q. lyrata) is found in swamps along rivers from North Carolina south and west, where it forms a large tree, 70 to 80 ft. high, with its seven to nine triangularly lobed leaves crowd- ed at the ends of the branches. The acorns are an inch long and considerably broader, and enclosed in a cup which is clothed with rugged scales and almost conceals the nut. In the group of chestnut oaks the leaves are not lobed (except slightly in one species), but are coarsely sinuate-toothed, and white or whitish-downy beneath ; the cup hoary, hemi- spherical or somewhat depressed, about half as long as the oblong-ovoid edible acorn. The swamp white oak (Q. bicolor) is found in low grounds, especially in the northern and west- ern states, and frequently attains a large size ; its leaves are intermediate between the chest- nut and white oaks, being sometimes simply sinuate on the margin, and at others more pinnatifid than toothed, but in all cases wedge- shaped at the base, and hoary beneath with a soft down. After flowering the foot stalk elongates, and when the fruit is mature is 2 or 3 in. long, or longer than the petioles, and bears one or two acorns an inch long ; the cup has its upper scales awn-pointed, and some- times forming a.mossy fringe around the edge. The wood is brownish, heavy, and compact; its uses are similar to those of white oak. The chestnut oak (Q. prinus) has given botanists much trouble on account of its variable char- acter. The leading form is popularly known Swamp White Oak (Quercus bicolor). as the swamp chestnut oak ; it has obovate or oblong leaves undulately toothed on the mar- gin, minutely downy beneath, with 10 to 16 pairs of straight rather prominent primary ribs. The fruit-bearing stalk is shorter than the petioles; the acorn is an inch or less in length, with a thick cup covered with hard stout scales. This is found from Pennsylvania southward, and is most plentiful in the Caro- linas and Georgia, inhabiting moist and dry soil, and differing much in size and the qual- ity of its wood according to its situation. It makes durable rails. A variety of this is the rock chestnut oak (var. monticola}, given in some works as a species (Q. montana); it is found in or near the mountains, from Ver- mont southward, and forms a tree 30 or 40 ft. high ; it has large acorns, like the preceding, and more chestnut-like leaves; it produces greatly superior timber, and is highly esteemed as fuel. It is a most valuable tree for plant-