Notes from the Landscape: Winter Tree Identification

An identifying feature of the Shagbark hickory are lenticels; small pore-like structures on the twig that allow the exchange of oxygen and carbon dioxide

 

Trees can be identified in winter by looking at the shapes formed by their trunks and bare limbs. Each tree species has a distinct shape, and its bark, twigs, and inactive buds give clues to help reveal its identity.

To find the answers all you need is a key. A key uses a series of paired questions in which each alternative leads to the next unique question. The questions begin with general tree characteristics and end with individual traits that are specific to only one species.

 

 

Samaras - The winged fruit of ash trees

Typical twig parts described in the key include buds, leaf scars, pith, bundle scars, lenticels and others, so it is necessary to learn the structural features of woody plants to effectively use the key. Other helpful features are the tree’s architecture or overall shape, bark, remnants of fruits and seeds, thorns, scents, and unique characteristics.

Choosing a key that is specialized for a certain geographic region or habitat will make the process faster and easier. Uncommon species and cultivated varieties used in the ornamental landscape may or may not be included. Some helpful resources are Winter Tree Finder: A Manual for Identifying Deciduous Trees in Winter (Eastern US) and Fruit Key & Twig Key to Trees and Shrubs. These books use a dichotomous (divided in two parts) key as described above. The Tree Identification Book: A New Method for the Practical Identification and Recognition of Trees uses pictorial keys and “master pages” that place all of the important features of a tree in one place. This book includes leaf depictions as well as twigs and buds, bark, fruit, and flowers in separate visual keys so that side by side comparisons can be made, often with actual size images.

Honey locust do not always have thorns. Popular modern cultivars of this tree are thornless.

 

 

To help study individual characteristics a hand lens, small folding knife and binoculars may aid in examination. Observation of the local site condition such as soil type, elevation and situation are clues that can help determine what types of trees are most likely to exist there. Consider whether the trees are naturally occurring or planted. Some foreign trees have established themselves in our landscapes and may be found mixed among common native species. Realize too that variations exist within species so a particular specimen may exhibit slightly different traits than its kin. Structural damage or disease may also affect the appearance of the tree.

Winter Landscape Trek on the grounds of Fort Ticonderoga

 

 

 

 

Using a key can open the door to learning more about the landscapes around you. Trees provide year-round beauty and enjoyment and winter is the perfect time to appreciate the details often overlooked in other seasons. Fort Ticonderoga offers opportunities to explore our landscape throughout the year to study topics including nature, history and horticulture. I hope to see you in the 2012 season!

Heidi teRiele Karkoski
Curator of Landscape

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