C. tomentosa, Mocker-Nut Hickory, so called in consequence of the smallness of the kernel compared with the size of the nut. Its leaflets are from 7 to 9 in number, slightly round, very downy on the under side ; they become bright-yellow in the autumn. The leaf-buds are thick, short, whitish-gray, and very hard in the winter season. The nuts are sessile, roundish, and inclosed in a rind which only opens half-way to let them drop out ; they are light-brown, angular, and very little pointed. The bark of this species does not scale off, but rends into deep fissures. It grows the slowest of all the hickories, and is found chiefly in forests from New England to Virginia and in the Alleghenies ; Pursh says in fertile soils, but 31ichaux adds that it nevertheless is the only hickory which makes its appearance in those sterile tracts called pine-barrens, where however it is only a scrubby bush. In the most favourable situations it rarely grows more than 60 feet high, and is usually a gnarled inelegant tree. Nuttall mentions a variety of this species as occurring a few miles from Philadelphia, with "fruit nearly twice the ordinary size, as large as an apple." C. enicrocarpa. Leaflets about five, oblong-lanceolate, sharply serrate, and obviously tapered to the point ; smooth on each side, glandular beneath. Fruit roundish, with a small thin-shelled nut, which is somewhat quadrangular and abruptly rounded at the end, with a very small point. According to Nuttall this is found wild on the banks of the Schuylkill, in the vicinity of Philadelphia, where it forms a large tree with an even bark. The fruit is much like that of C. tomentosa, and eatable, but very small, not exceeding the size of a nutmeg.
C. amara, Bitter Nut, or Swamp Hickory ; found from the state of Vermont in the north, as far as the most southern parts of the Ame rican Union. In woods near New York, Michaux measured several individuals which were 10 or 12 feet in circumference, and from 70 to 80 feet high ; but in general it is smaller. It is the latest in leafing of all the hickories. The leaflets are from 7 to 9 in number, smooth, coarsely and irregularly serrated; long, lanceolate, and more wrinkled than in other species. The fruit is small, roundish, with a thin rind ; the nuts are obovate, depressed at the end, with a central projecting point ; they have no angles, and are broader than they are long; the shell is thin and brittle, and the kernel so bitter and austere that even squirrels refuse to eat it. This species is easily known in winter by
its yellow buds.
C. aquatica, found only in the lower parts of the southern states of the American Union, in swamps, and by the aide of ditches surround ing rice-fields, along with red maples, deciduous cypresses, and Carolina poplars. It is readily known by its very narrow taper-pointed leaflets, which vary in number from 9 to 11. Its fruit is small, ovate, tuber culated, angular, and placed upon stalks in little clusters. The nuts are bright brown, ovate, angular, but little pointed at either end they are very thin-shelled, and contain an extremely little kernel. The tree grows from 40 to 50 feet high, and is of much less value than the other species.
C. porcina, the Pig-Nut Hickory, or Hog-Nut. This is most com mon in the middle states, beginning with Lancaster County, Penn sylvania, in the north. It is one of the largest trees in the United States, growing to the height of 70 or 80 feet, with a diameter of 3 or 4 feet. Its brown shoots and oval very small buds distinguish it in winter. The leaflets are lanceolate, very taper-pointed, regularly serrated, and from 3 to 7 in number ; they are quite smooth on each side, and on vigorous shoots in shady places their stalks are violet. The fruit is sessile, and varies in form from pyriform to spherical : its little nuts correspond in this respect with their rind ; they are scarcely at all angular, and always rounded at the apex, with a sharp point ; the shell is very thick and hard ; the kernel sweet but small, and difficult to extract.
C. myriaticceformis, Nutmeg Hickory. 'This is a little brown species, of which Michaux obtained a single branch with about 30 nuts at Charlestown from a negro gardener, who procured them in the neigh bourhood of that' city. Its leaves are like those of C. aquatiea, but not quite so long and narrow. The fruit is sessile, oval, tuberculated, and contains a small smooth brown striated nut, with an exceed ingly thick shell, and a very small kernel. Elliott, who resided near Charlestown, and wrote ou the plants of Carolina, could never gain any further intelligence of this plant.
(Michaux, Arbres Forestiers de 'Amerique Septentrionale.)