Tag: trees

by Elizabeth Heighington

On February 18, 2026, Gart Bishop presented a fascinating and informative workshop on how to identify New Brunswick trees and shrubs during the winter. Gart, Liz Mills, Bev Schneider and Clay Merrithew, all “Friends of the Herbarium”, collected fresh branch and twig specimens from local trees and shrubs. Specimens, some with attached catkins and fruit, covered two long tables in the lab, and books covered a third table.

Here are a few of the books:

Gart began the PowerPoint presentation by illustrating select species, and showing us how to identify them without the presence of leaves, flowers and in most cases, fruit. Identifying deciduous trees and shrubs in the winter can be difficult, but by examining certain features and asking simple questions, you can succeed.
Diagnostic features include:
1. Branching pattern or leaf bud arrangement. Alternate or opposite?
2. Leaf buds. Size, shape, number of scales or no scales, hairs or no hairs, sticky?
3. Stipule scar. Shape?
4. Pith. Colour, shape?
5. Twig. Colour, lenticels, odour when scraped or peeled?
6. Bark. Colour, texture?
7. Fruit. Any remaining fruit? What does it look like?
8. Flower buds. Visible?
9. Unique features. Galls?

Using dissecting kits and microscopes, we examined the fresh specimens. Hobblebush (Viburnum lantanoides), a common early flowering shrub, has opposite buds and no bud scales. Willows (Salix spp.), common early flowering shrubs, have alternate compressed buds with only one bud scale. I learned that you can easily identify Red-tipped Willow (S. eriocephala) by the presence of pinecone galls on the tips of some branches. Pinecone gall is almost exclusively found on this willow species.

Some species such as Chokecherry (Prunus virginiana) have alternate buds with many bud scales. When you peel or scrape the bark of Chokecherry you can smell a bitter earthy odour from hydrogen cyanide released by the fresh tissue. The desiccated light brown leaves of American Beech (Fagus grandifolia) often remain on the tree until late winter which makes identification easy. However another diagnostic feature are the large, long, narrow buds with imbricate scales and a visible stipule scar present even when the leaves have fallen off.

Alder (Alnus spp.) is a thicket forming shrub, but two common species in New Brunswick can be difficult to differentiate. The stalked buds of Speckled Alder (A. incana ssp. rugosa) distinguish this species from Green Alder (A. viridis ssp. crispa). Separate male and female catkins (monoecious) often remain on the branches during the winter, and are helpful for identification.

Pith colour can help you distinguish between similar looking species. Black Elder (Sambucus canadensis) has a white pith and Stinking Elder (S. racemosa) has an orange pith. Butternut (Juglans cinerea), a declining tree species due to Butternut canker disease, has alternate buds, a long terminal bud, and is the only native species with a chambered pith. You can clearly see the chambered pith when you cut the branch on the diagonal.

Beaked Hazelnut (Corylus cornuta), a monoecious shrub, has male and female flowers that open in early spring before the leaves. The male catkins are visible in the winter, but the female flowers are hidden in tiny buds. The female flower buds are rounder than the leaf buds.

Birch trees (Betula spp.) have alternate buds and when young the different species can look similar. You can easily identify Yellow Birch (B. alleghaniensis) by scraping the bark to release the wintergreen odour. Odour is also a diagnostic feature of Sweet Gale (Myrica gale), a common shrub in bogs. When you crush the buds, a nutmeg odour is released.

These are just a few examples of the species we examined during the Botany Blast workshop, and the skills we acquired to identify trees and shrubs during the winter. Walking in the winter woods of New Brunswick is magical. Knowing the names of the trees and shrubs surrounding you makes the walk even better.

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