Identifying Hardwoods Growing on Pine Sites

Clair A. Brown Harold E. Grelen
Southern Forest Experiment Station U.S. Department of Agriculture, Forest Service General Technical Report SO-15
The authors thank Bryan A. Jowers, Glendale, California, for the excellent winter silhouettes. For help in obtaining specimens or photographs of species not easily accessible to us, we thank the following: Roger W. Barbour, University of Kentucky; William Harlow, College of Environmental Science and Forestry, State University of New York; Richard Johnson, Caroline Dormon Nature Preserve; Betty E. Lemon, University of Southwestern Louisiana; R. Dale Thomas, Northeast Louisiana University; and Lino Della-Bianca and Edwin R. Lawson of the U.S. Forest Service.
This publication illustrates and describes 26 hardwood species or varieties, including 16 oaks and hickories, with photographs of leaves, bark, buds, flowers, and fruits. Line drawings feature the winter silhouette of each species and a key is included to assist in identification.
US. Department of Agriculture Forest Service General Technical Report SO-15
CLAIR A. BROWN Professor Emeritus, Department of Botany Louisiana State University Baton Rouge, Louisiana
HAROLD E. GRELEN Principal Range Scientist Southern Forest Experiment Station Forest Service—USDA Pineville, Louisiana
1977
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402
Percentages were derived from Staff, For. Resour. Res. Work Unit (1976). Nomenclature used herein follows Little (1953).
Hickories have alternate compound leaves with 5 to 13 leaflets. They are monoecious; that is, the stamens and pistil are borne in separate flowers on the same plant. Flowers generally develop after the leaves are three-fourths to full grown. Staminate flowers are in catkins, which occur on last year’s wood and usually have three branches. The stalkless pistillate flowers are in several-flowered spikes at the apex of the current season’s growth. Catkins last from 10 days to 3 weeks and are usually not useful in distinguishing the species. The fruit, however, is widely used for identification. The husk may be very thin (about 1 mm), moderately thick (3 to 5 mm), or very thick (more than 5 mm). Similarly, the shell may be thin, moderately thick, or very thick. The meat varies from sweet to bitter. Upon drying, the husk usually separates along sutures and frees the nut. In some species the husk partly splits at the sutures but still encloses the nut when it falls. Such nuts are usually sterile, because the meat is seldom filled out.