Notes on Forestry and Wood-Use
Purdue University Cooperative Extension Service Lafayette, Indiana
Mimeo F-43 February 1963
HOW TO IDENTIFY SOME COMMON INDIANA WOODS
W. L. Fix and E. J. Lott*
Woods differ in strength, hardness, color, odor, weight and other properties, as well as in structure. These differences are used in their identification.
To identify an unknown wood, cut a smooth surface on the end or cross section of the sample using a sharp knife. Here you will see the annual rings just as they appear on a stump in the woods. Using a hand lens now check to see if openings, called pores, can be seen within the annual rings . The pores, easily seen in oaks, ash, and hickory, are tubes which carry water and nutrients from the tree roots to the leaves.
In some hardwood (broadleaf) trees, the pores may be larger on one side of the annual ring. The area containing the larger pores, which is always on the side of the annual ring towards the center of the tree, is called springwood and grew during the early spring season. The area of smaller pores, along the outside of the annual ring, grew during the summer and so is called summerwood. Thus, an annual ring is made up of a band of springwood and a band of summerwood.
Woods having large pores in the springwood and small pores in the summer-
wood are called ring-porous woods. These include the oaks, elm, ash, and others. Woods having springwood and summerwood pores about the same size are called diffuse -porous. Among others, these include sycamore, tuliptree, beech and the maples. A few other woods such as walnut and cherry have a gradual change from larger springwood pores to smaller summerwood pores. These are often called semi-ring-porous woods. The first step, then, in wood identification of the hardwoods is to separate the woods into one of these groups.
In a few species the large springwood pores may appear under the hand lens to be closed, or filled. White oak is a member of this group (see sketch).
In some species groups of cells will be found in the summerwood arranged in various patterns. These may be roughly triangular in shape (as in white oak), in short lines (as in red oak), wavy horizontal bars (as in red elm), in small isolated clusters, or may appear as more or less continuous fine lines (as in hickory). These serve as additional aids to identification of many species.
* W. L. Fix is Extension Forester at Jasper, Ind., and E. J. Lott is State Extension Forester at Purdue University, Lafayette, Ind.