HICKORY. The hickory trees are natives of North America, and belong to the genus Carya of botanists. They are closely allied to the walnuts (.raglans), the chief or at least one very obvious difference being that, whilst in Carya the husk which covers the shell of the nut separates into four valves, in Juglaus it consists of but one piece, which bursts irregularly. The hickory trees are of lofty growth, ant are held in high estimation, both on account of their durable timber, and from the excellent nuts which some of the species produce. The timber is both strong and heavy, and remarkable for its extreme elasticity, but it is not much used either for shipbuilding or for architectural purposes, as it decays rapidly when exposed to heat and moisture, and is peculiarly subject to the attacks of worms. It is very extensively employed in manufacturing musket stocks, axle-trees, screws, rake teeth, the bows of yokes, the wooden rings used on the rigging of vessels, chair backs, axe-handles, whip-handles, and other purposes requiring great strength and elasticity. Its principal use in America is for hoop-making ; and when it is remembered how large a proportion of the productions of the United States is packed in barrels, some estimate may be formed of the consumption of hoops and of the consequent demand for hickory wood, which is the only American wood found perfectly fit for that purpose.
The wood of the hickory is of great value as fuel, on account of the brilliancy with which it burns and the ardent heat which it gives out, the charcoal being heavy, compact, and long-lived. The species which furnish the best wood are Carya alba (shell-bark hickory), C. tomentosa (mocker-nut), C. olivaformis (pecan or pavane nut), and C. porcine (pig-nut), that of the last-named, on account of its extreme tenacity, being preferred for axle-trees and axe-handles. The wood of C. alba splits very easily and is very elastic, so that it is much used for making whip-handles and baskets ; the whip-handles are greatly esteemed for their suppleness, and considerable numbers of them are annually imported into England. The wood of this species is also used in the neighbourhood of New York and Philadelphia for making the back bows of Windsor chairs. The timber of C. amuse and C. aquatica is considered to be of inferior quality.
Most of the hickories form fine-looking noble trees of from 60 to 90 feet in height, with straight, symmetrical trunks, well-balanced ample heads, and bold, handsome, pinnaled foliage. When confined in the forest they shoot up 50 or 60 feet without branches, but when standing alone they expand into a fine head, and produce a lofty round headed pyramid of foliage. They have, observes Downing, all the qualities which are necessary to constitute fine graceful park trees, and are justly entitled to a place in every considerable plantation. The most ornamental of the
species are C. olivaformis, C. alba, and C. porcine, the last two also producing delicious nuts, and being worthy of cultivation for their fruit alone.
The husk of the hickory nut, as already stated, breaks up into four equal valves or separates into four equal portions in the upper part, while the nut itself is tolerably even on the surface, but has four or more blunt angles in its transverse outline. The hickory nuts of the American markets are the produce of C. alba, which is called the
shell-bark hickory because of the roughness of its bark, which becomes loosened from the trunk in long scales bending outwards at the extremities and adhering only by the middle. The nuts are much esteemed in all parts of the States, and are exported in considerable quantities to Europe. The pecan-nuts, whirls come from the Western States, are from an inch to an inch and a half long, smooth, cylindrical, pointed at the ends, and thin-shelled, with the kernels fall, not like those of most of the hickories divided by partitions, arid of delicate and agreeable flavour. The thick-shelled fruits of the pig-nut are generally left on the ground for swine, squirrels, &c., to devour. In C. amara the kernel is so bitter that even the squirrels refuse to eat it.