HOLLIS – On the morning of Jan. 19, a small group met in the barn classroom at Beaver Brook’s Maple Hill property to learn a little bit more about local trees.

The conversation focused on how to identify a tree in the midst of winter when many have no leaves.

Led by Mila Paul, of the New Hampshire State Forest Nursery, and Celeste Barr, director of education at Beaver Brook, the lecture began with tree clippings, leaf needles and an interactive discussion.

The discourse aimed at identifying a manageable number of species, 10 in total, all common in most local woodlands.

Many of the 10 species have common relatives easily mistaken for one another, so Barr and Paul invested a fair amount of time to help the students distinguish different species.

Paul passed around a drab gray twig with nothing on it but a few buds, and asked her students, “Can anyone tell me what this is?”

The room fell silent.

“Are the branches opposite or alternating?” she asked. “Are the buds pointed or round?”

Paul guided them with more questions until it became clear the twig came from a sugar maple.

Paul said this process of elimination by characteristic quality, called cladistics, is the key to identifying a tree when you have only a limited sample, such as a twig, or a leafless tree’s crown in winter.

Armed with a few facts about each of the trees, a new method for identification and cramp-ons, Barr and Paul led the class out to the woods behind the barn.

After a brief stop at the edge of the forest, where Paul pointed out two clumps of sumac, comparing the buds and bark, the harder task of identifying massive trees with branches and buds up high began.

At one tree Paul asked, “It this white or red oak?”

The class soon realized that just looking at the crown of the tree 50 or more feet in height would not suffice.

Barr led a search of the area beneath the tree looking for clues, since a branch with withered leaves or an acorn or two might solve this dilemma.

During the walk, Barr, Paul and Wendy McDouggal of Littleton, Mass., scavenged beneath a pine tree to find a fallen branch with needles, hoping to count the number in a bunch to identify the towering giant as a red pine or a white pine.

By the end of the short walk everyone clearly had a better understanding of tree identification and perhaps an increased interest in the trees as well.

Anyone interested in learning more about identification of trees and shrubs or to take a tour should contact Beaver Brook at 465-7787.