Experienced naturalists can usually identify trees by glancing at them from a distance. In some cases, this ability is based on specific characteristics, such as branching pattern or bark texture. For example, the floppy leader of eastern hemlock reliably separates it from other conifers. In many cases however, trees (and other plants) can be identified by a general impression rather than anything specific. With experience, one develops gestalt images of familiar species. Gestalt theory is based on the idea that human brains attempt to simplify and organize complex images by subconsciously arranging the parts into an organized whole, rather than just a series of disparate elements.
OK, but what if you lack enough experience for your brain to have organized woody plant morphology for you? During the growing season, leaves are often the easiest distinguishing features to use, but here in the UP the hardwood forests are leafless for more than half the year. Although bark can work for tree id, the textures and colors involved can be tricky, as these characteristics are quite variable and overlap among species.
Enter Sensuous Twigs. Well, you have to go out and find them, but twigs are worth going to for a couple of reasons if you're curious about trees' lives. The first is that twigs are where several distinctive structures, such as buds and leaf scars, occur (see twig diagram p. 16). These structures make twigs much more definitive than bark for tree id, and they tell you about the trees health by revealing twig growth rates. Twig parts are very small, however; so they only tell you who they are and how they are doing if you look them in the face real closely. The second reason to get close to twigs is simply to see their sensuous beauty. Here are a few examples to wonder about.
1 - Sugar Maple (Acer saccharum) Dormant Twig. This twig shows one year of growth. The buds are opposite each other and have many overlapping scales (imbricate). The rings around the twig at the bottom are last year’s terminal bud scale scars.
Sugar Maple Dormant TwigThis sugar maple (Acer saccharum) twig shows one year of growth. The buds are opposite each other and have many overlapping scales (imbricate). The rings around the twig at the bottom are last year's terminal bud scale scars.
2 - Striped Maple (Acer pennsylvanicum) dormant twig. Striped maple buds have only two ‘valvate’ bud scales which meet like clam shells. Striped maples are sequential hermaphrodites, meaning that they can change their sex as they age.
Striped Maple TwigStriped maple (Acer pennsylvanicum) buds have only two 'valvate' bud scales which meet like clam shells. Striped maples are sequential hermaphrodites, meaning that they can change their sex as they age.
3 - Willow (Salix sp. - unknown species) Twig. Willow buds have single bud scales (actually two fused scales) that must split to open as shown here.
Willow TwigWillow (Salix spp.) buds have single bud scales (actually two fused scales) that must split to open as shown here.
4 - Pin Cherry (Prunus pennsylvanica) Twig. Pin cherries, like other trees with heavy fruits, bear their fruit on short, strong spur shoots.
Pin Cherry Flower BudsPin cherries (Prunus pennsylvanica), like other trees with heavy fruits, bear their fruit on short, strong spur shoots.
5 - Paper Birch (Betula papyrifera) Catkins. Paper birch produces separate male & female flower buds (catkins) on the same tree.
6 - Black Cherry (Prunus serotina) Twig. Black cherry has alternating (not opposite) lateral buds and true terminal buds. Like other cherries, the twigs have a ‘stinking almond’ smell when broken.
7 - Red Elderberry (Sambucus racemosa) Flower Buds. The Elder Wand, made from the branch of an elder tree, plays a pivotal role in the final book of the Harry Potter series.
Red Elderberry Flower BudsRed elderberry (Sambucus racemosa) has a long history of medicinnal uses. The Elder Wand plays a pivotal role in the final book of the Harry Potter series.
8 - Common Lilac (Syringa vulgaris) Leaf Buds. Lilac is in the olive family (Oleaceae), native to the Balkan Peninsula, where it grows on rocky hills. Note how the bud scales are elongating.
9 - Black Ash (Fraxinus nigra) Leaves Emerging. All our ash species are threatened with near-extinction by the exotic Emerald Ash Borer (EAB).
10 - Red Maple (Acer rubrum) Flower Buds. Red Maples can produce all male flowers, all female flowers, or some of both.
Red Maple Flower BudsRed maple trees (Acer rubrum) can produce all male flowers, all female flowers, or some of both.
11 - Bigtooth Aspen (Populus grandidenta) female catkins. Note the pointed leaf buds still tightly closed. Flowering before leaf-out helps aspens spread their pollen, which comes from male catkins on separate trees.
Bigtooth Aspen Female CatkinsBigtooth aspen (Populus grandidentata) flowers before leafout helping their pollen spread better in the wind. Male and female catkins occur on separate trees. Note the pointed leaf buds still tightly closed.
12 - Common Lilac (Syringa vulgaris) Flower Buds Expanding. Lilacs are very hardy and excellent food plants for butterflies.
Common Lilac Flower BudsLilacs (Syringa vulgaris) are very hardy and are excellent food plants for butterflies.