HICKORY, a group of trees of the walnut, forming the genus Hicoria, and exclusively North American. They are large strong trees, 60 to 80 feet high, with close shaggy bark and large pinnately divided leaves, pistillate flowers on a terminal peduncle and staminate flowers in long, drooping aments. The fruit is a thick shelled nut in a tough green husk. There are about 10 species, all natives of the eastern United States and Canada except a Mexican species. The best known of these are the fol lowing: Shag-bark, shell-bark or white hick ory (H. ovata), leaflets 5 to 7, whose bark scales off in great plates curving outward at both ends, and whose nuts are sweeter and better than those of any other species; the northerly °big shagbark* or king-nut (H. laciniosa), leaflets 7 to 9, with narrower (shags,* darker wood and big nuts in husks often three inches long; white-heart, or fra grant hickory, or mocker-nut (H. alba), noted for the hardness and toughness of its wood; the pignut or broom hickory (H. glabra), leaf lets 3 to 7, which represents a group of mois ture-loving species whose nuts are thin-husked, elongated and bitter and astringent to the taste.
Uses of Hickory-wood.— As timber this wood is of great value for articles requiring great strength with lightness and elasticity; but it is liable to quick decay when exposed to the atmosphere, and for this reason is little used in buildings, and should be painted. It was the most serviceable of all woods to the aboriginal Americans; and the axe, pick and tool handles made from it are exported to all parts of the world. It enters into the manufacture of
rakes, cradles and many forms of farm-imple ments; is largely used in carriage-making, espe cially for thills, shafts and the parts of racing sulkies, the lighter American vehicles owing their acknowledged pre-eminence largely to the availability of this wood. The wood of the various species differs in quality, however; that of the pecan is hard and brittle, and the water hickory soft and comparatively light. The wood of the others is exceedingly strong and tenacious, and weighs about 50 pounds to the cubic foot.
Insect Pests.—A. S. Packard recorded in 1890 170 species of insects attacking the hick ories; and Chittenden declared in 1903 that this number could be easily doubled. Hickory ap pears to be an especial favorite of borers. Prominent among them are the painted hick ory-borer, one of the long-horned beetles (Cyllene picta)•, the hickory twig-girdler (Oncideres cingulata), (Elaphidion villosum), and hickory-bark beetle (Scolytus quadrispinosus). This bark-borer is the most Important economic species, and during recent years has been the cause of considerable injury in hickory forests in the State of New York. Consult Packard, 'Insects Injurious to Forest and Shade Trees,' published in 1888 as the fifth report of the United States Entomological Commission.