”Winter Twigs” is a guide to the wintertime identification of deciduous plants in the western sectors of Oregon and Washington.

Originally published in 1962, the revised edition is the definitive book on identifying plants during the months they lack the leaves and flowers that other field guides rely on.

Written by Helen M. Gilkey and Patricia L. Packard, ”Winter Twigs” covers 82 species and includes a glossary of botanical terms as well as more than 100 line drawings to help in identification.

”The logical time of year to become acquainted with deciduous trees and shrubs – that is, those which normally drop their leaves in autumn – would seem to be spring or summer when they are readily recognizable by their flowers and fruits,” the pair write. ”But winter is far from the sterile season which it superficially appears.

In fact, when winter woods are leafless and bare, and nature is stripped of her splendor; when twigs and branchlets stand out ‘gainst the sky graceful and dark and slender … we may find the most stimulating conditions for such study since our ingenuity is pitted against subtle characters, but just as definite indicators, of a plant’s identity as are blossoms and seed pods.”

Gilkey was professor of botany and curator of the Herbarium at Oregon State University for more than 30 years. She was the author of several books, including ”Handbook of Northwestern Plants.”

Packard, a former student of Gilkey, was professor of biology at Albertson College of Idaho.

Published by Oregon State University Press, ”Winter Twigs” is a 118-page softcover. It retails for $19.95.