You know what I like most about winter? It’s the one time of year when I don’t have to feel guilty about neglecting the garden. It’s my duty to neglect it!
But I can never let well enough alone, so this winter I signed up for several more courses offered through the Native Plant Trust. Most recently completed: one course on soils, one on trees of New England. These gave me numerous opportunities for guilt: they had homework assignments.
Brace yourself: I’m going to share with you my experience with the homework assignment for one of those courses. I’ll spare you the soils. I loved that course, but I mustn’t try your tolerance of my geeky tendencies toooooo far. So let’s head for the trees.
The mission …
Here was our challenge: take a walk in a wooded/forested area. Identify as many tree species as possible. Locate different species in canopy and understory, noting changes in species mix at different elevations or in wetter/dryer habitats, and maybe even figuring out the chosen woodland’s history.
I never got to any but the first part. By the time you finish reading this, you’ll understand why.
I’m used to trying to identify trees by examining their leaves. Identifying a tree in February in New England posed a problem. With the exception of pines and hemlocks and cedars and spruces, the trees are naked. Starkers! I’ll admit one exception: the oaks tend to hang onto a lot of their dead leaves. That practice used to seem deplorable, until I was straining to spot at least one deciduous tree I could be sure of.
How do you identify a tree without its leaves on? You can’t trust the leaf litter on the ground if you’ve ventured into a mixed stand; the winter blasts have already done a promiscuous mashup there. In the woods, you can’t go by the tree’s shape—you know, maples looking like a fat bouquet and elms making like a vase. No, trees growing together in the arboreal equivalent of cheek by jowl have had to elbow and shoulder their branches in wherever they can find a patch of light, and hope for the best.
So what can the avid (desperate?) identifier do?
Two things. Possibly the best, or so my botanist friend M maintains, is twigs with buds. If I had a stand of 5-foot trees, I’d choose that for sure. However, when everything but the trunk is 20 feet up or higher, you can kiss the buds goodbye. What you’re left with is bark.
Barking up the trees
About a year ago I tuned in on a forestry school’s guest speaker talking about bark. He was earnest. Intense. Totally in love with tree bark. And about as absorbing as watching a tectonic plate move (between earthquakes) in real time.
Heaven forfend that I do that to you! So I won’t go into all the finer points about bark (cambium layers and all that jazz, for example).
You may already know some of the obvious distinctions. Paper birch, for example: that dramatic stark white bark, curling itself away from the trunk in artistic scrolls. Come to think of it, that’s just about the only easy distinction, unless you resort to exotics like shagbark hickory, or the ghastly graveyard look of sycamores.
For the rest, you can find a lot of variation. In textures, from smooth to roughly ridged; in colors, ranging grayish white to greeny gray to reddish brown to nearly black; in patterns running from scales to shingles to slabs to parallel furrows to a crazy crisscross or a crazy quilt of Ns and Ys.
Every species is different. Except that sometimes they aren’t. Or sometimes, the bark on a young maple looks much like the bark of a mature or even ancient beech—and not at all like the bark of a mature or ancient maple.
Then there are the oaks, which hybridize all over plant kingdom come, so you can find “white oak” leaves fluttering from a trunk with “red oak” bark.
Should you accept it…
So how do you (I) figure out the ID? We were urged to use one or more of the dichotomous keys that various books and plant identification sites provide.
Here’s how a dichotomous key works. Imagine you’ve had to rush to the emergency room, and (assuming it’s not a Saturday night riot scene) the doctor tries to diagnose your problem before she can fix it. She whips out her Dichotomous Key Diagnostic Book, and starts to work.
- Is the patient visibly bleeding?
- If yes, go to 2
- If no, go to 945
- Is there a lot of blood?
- If yes, go to 3
- If no, go to 500
- Is the blood
- Spurting intermittently? Go to 4
- Flowing steadily? Go to 250
- Is the spurting coming from
- The neck? Go to 5
- Anywhere else? Go to 80
You get the idea. Thank heaven they’re not using dichotomous keys in the ER. By the time the doctor has figured out that you’re bleeding out from your femoral artery, she may be at
499. Patient has bled to death.
Fortunately, none of the trees were visibly bleeding.
Ready for the tree hunt now?
Into the woods—not
For the tree identification exercise, I walked along the edge of a woods owned by a nearby farm. I had planned to walk into the woods to get a good look at interesting trees, but found my way impeded by undergrowth (lots of multiflora rose invaders), random barbed wire, and deep mud in the pathways and trails. There was enough, though, to occupy me just along (mostly) the edges.
I took Michael Wojtech’s Bark guide with me, as well as the Wattses’ Winter Tree Finder, but quickly realized that out among the trees was not the best setting for flipping back and forth through the dichotomous keys.
Instead, I took photos. That meant trying to get shots of the whole tree—not always possible if neighboring trees crowded too close, especially if they were evergreens and blocked the upward view entirely—as well as some closeups. Then I went home and started trying the identifications from the photos using the dichotomous keys.
It went downhill from there, except when I’d managed to nab a leaf and/or twig sample as well. In a couple of cases I also checked against more photos on some websites (see below about those). I still ended up unsure of the identifications of most of the trees I’d photographed. Of the 20+ trees (including some clumps of trees counted as one each), I managed fairly certain identifications of only two; all the rest have question marks attached.
How dry I’m not
I did use one exclusion to narrow down the choices. For example, a couple of trees’ bark seemed to look a lot like hop hornbeam (Ostrya virginiana). But Wojtech (118-119) describes its habitat as “Dry, rich sites, most often on slopes and ridges….”
This area, though, sits in a kind of depression and the water stays there (and beaver activity in a contiguous swamp has helped keep it wet). On my tree walk, which took me to a part of the woods I hadn’t explored before, I found some major drainage ditches: one bordering the woods, and several leading into them, some alongside paths. Even so, and although the rains hadn’t been so very recent, the ground was still very wet and the trails were inches deep in mud.
From this I concluded that the trees I was most likely to find growing there would be the species that don’t mind wet feet. Exit hop hornbeam, although from the pix in the books it looks like a lovely tree. I may look for space to plant one in my yard. I can do dry! Just ask my gasping maple and birch.
From near certainty
So, what trees did I find? (Or more accurately for most of them, do I think I found?)
As the landscape shot at the top of this post makes clear, this area is a mixture of evergreens and deciduous trees. The evergreens seemed to me to consist primarily of Eastern white pine (Pinus strobus). I confirmed the identity of a couple of those, thanks to their being small and having that convenient habit of producing needles in clumps of five, and growing close enough to the edge of the scrum that I could get a good look and/or a sample. These included Tree 05 and Tree 15:
To almost near certainty
The other identification I’m pretty sure of, Tree 12, is a white oak (Quercus alba). This tree had a double trunk, part of which might qualify as a blasted oak, since the base of the trunk looked much the worse for wear. The upper parts of the trunks looked to be in pretty good shape, but were so thick with lichen that I had to resort to studying a bare part of the blasted trunk to match the bark to a mature white oak.
I’m grateful in this instance that oak trees hang onto many of their dead leaves. The leaves on twigs and branches had rounded edges, like those of white oak.
This tree also had several old round oak bullet galls (created by cynipid wasps) that were easy to spot, and one that was close enough at hand to photograph. That confirmed at least the Quercus if not the alba.
Another much younger oak, Tree 14, has me wondering whether I spotted one of those notorious hybridized specimens. The leaves looked to me very much like white oak, but the bark looked like young Northern red oak (Quercus rubra).
But why should I have all the fun? How about you try to figure out what some of the others were? I’ll give a prize book to the person who provides the best (not necessarily the correct) answer/s.
Below, you can find photos for three of the trees I never felt sure of. The photos are fairly low resolution (that’s so this page won’t load like molasses in March), but if you click on them, it will take you to the higher-resolution originals. I provide you with a handful of species possibilities to narrow it down. You probably don’t have the books, but you can check against a couple of online sources:
- iNaturalist (https://www.inaturalist.org/home ; you may have to register on the site to use it, but it’s free). This is like a crowd-sourced platform pulling in observations by people like us, along with scientists and various experts who help with authoritative identifications. It does not use dichotomous keys.
- Go Botany (https://gobotany.nativeplanttrust.org). This site gives you a choice of several different kinds of keys, and if desperate, you can register for the PlantShare section to upload plant photos and Ask the Botanist for identifications. The individual species pages have photos and descriptions that can help with identification. Note that Go Botany specializes in plants of New England. If you’re in a different part of the country, this may not help you with your local plants.
- For more photos and descriptions to check against, you could try the Missouri Botanical Garden Plant Finder (https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderSearch.aspx) and the North Carolina Extension Gardener Plant Toolbox (https://plants.ces.ncsu.edu).
On your mark
One other important clue for you: Remember the ground is pretty soggy, though not actually swampy.
Ready? You can post your answers in Comments. Just be sure to explain why you picked a particular species—the reasoning counts the most towards winning the prize. If you want to do only one or two, feel free. And don’t be ashamed to resort to the Sherlock Holmes principle: “Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.”
Tree 06: Smooth, unbroken bark with no vertical lines
This should be easy; there aren’t that many species with smooth bark. But the mottling and especially the ample growth of lichens on the trunk complicated the identification.
Do you think this tree is
- Downy serviceberry (Amelanchier arborea)
- Red maple (young) (Acer rubrum)
- American beech (Fagus grandifolia)
- Something else (name it!)
Why would you pick the one you pick?
Tree 09: Furrowed bark in long vertical strips, deeper and more broken up towards base
This wasn’t an especially healthy-looking specimen and it had too much company, so I don’t know whether its shape means anything. The trunk could have been any of several different possibilities. It was so thick in moss—not lichen, actual moss—that it was hard to be sure exactly what the bark looked like. I found plenty of maple and oak leaves along with a few elmy-looking leaves in the immediate vicinity.
Do you think this tree is
- Sugar maple (Acer saccharum)
- American elm (Ulmus americana)
- White oak (Quercus alba)
- Something else (name it!)
And why would you pick the one you pick?
Tree 11: Smooth, unbroken bark above; rough bark with vertical cracks at base
“Tree” 11 was actually a tight clump of several young trees. Almost all the bark, all the way up, was a smooth light gray (making allowances for splotches caused by lichen). But towards the base of a couple of the trunks the bark was rough, with long vertical cracks that looked like they might develop into furrows. Several of these small trunks had tiny twigs with a distinct reddish cast.
Do you think this tree is:
- Red maple (Acer rubrum)
- American beech (Fagus grandifolia)
- Silver maple (Acer saccharinum)
- Something else (name it!)
The surprise find: Tree 18
None of my tree books helped in identifying Tree 18. For that, I had to resort to running the photo past iNaturalist, which almost instantly furnished several possible matches, the first of which I discounted. Amur corktree? Native to Manchuria? Who could believe that!
But after I’d scratched my head and eliminated all other possibilities (ashes of various sorts among them), I uploaded the photos on iNaturalist for community identification. I also consulted my botanist friend M. Fortunately I had gotten a shot of the one twig I’d been able to reach.
One of the experts on iNaturalist confirmed the tree as an Amur corktree (Phellodendron amurense), and M clinched the identification by locating a photo of the twig, which looked like a perfect twin of the one I’d clipped. Sherlock Holmes was right!
Turns out the Amur corktree, which came in originally as an ornamental tree for lawns, has naturalized to forests in New England and beyond. Several states have designated it as invasive or as a “noxious weed,” because it crowds out native hardwoods. The female trees produce clusters of tiny fruits that must appeal to birds, which is all it takes to spread the seeds far afield.
Which gets us to the point:
This identification exercise, aside from imbuing me with new respect for the people who traipse blithely through the woods calling everything by its (generally European-descended human-bestowed) name, also increased my awareness of the fragile balance that keeps our trees with us.
The Amur corktree made for a dramatic example of the plant invaders that threaten the vitality of the woods we tend to take for granted. But there are plenty of other examples: multiflora roses abounded in my chosen area, and if I’d looked more closely I’m sure I’d have found plenty of others. Japanese barberry, for example. If you’re a New Englander, you may already be aware of the pervasiveness of purple loosestrife along roadsides and in wetlands. If you’re anywhere along the East Coast of the US, you might have heard of the growing (no pun intended–but: a foot a day!) problem of kudzu. And if you’re a gardener, you may already worry a lot about garlic mustard or Japanese knotweed taking over your beds.
These, and more (way too many more!), species of plants, were planted originally by well-meaning gardeners, farmers, highway departments, erosion control programs, and others. But unlike our politer visitors like peonies and lilacs and corn, the invasive species escape from their original plantings and begin crowding out native species. They rob the soil of nutrients, suck up the water, and shade out the light that other plants need to survive and thrive.
That’s bad news not just for our native plants, but for the wildlife species that depend upon them. I could say a lot more on that topic, but that’s another whole post (or two or three).
Our forests already face big threats from climate change and from the spread of (also often invasive) new bugs and blights. The least we could do is to think carefully before digging a spot for that gorgeous new plant we saw at the garden center, or accepting a free plant from a fellow gardener.
You can easily look up the plants to avoid by using a search engine. Just put in a search string with “[my region or state] invasive plant species” and you get good info from Audubon, National Park Service, and more.
And if you’re considering a specific plant, all you have to do is to search for “[name of plant] invasive?” You could also check to make sure that none of what you’re now growing is on the list of problematic species.
If we’re inclined to work within a larger arena, it wouldn’t hurt to check on what policies govern our town or city agencies’ decisions on what they plant in our public spaces. Or maybe even to get involved in the discussions leading to such decisions.
Okay, off my soapbox.
If you haven’t already done so, you can sign up for the newsletter, which is just a notice when a new post goes up. Whether you sign up or not, please post your comments below. I try to reply to every comment, but feel free to answer others’ comments yourself, too. Here are a few questions to get you started, but go for any topic this post or gardening in general inspires you to.
- What is your best guess for any or all of the tree identifications (tree 06, tree 09, tree 11), and could you give your reasons? You could be the proud winner of a book on trees!
- What’s your favorite tree, and why? (species or individual, doesn’t matter)
- Are any invasive plants particular problems in your area?
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