Birch Family

When one thinks of Birches, or the Birch family Betulaceae, this is what usually comes to mind. Trees with white peeling bark. The family is more complex than that, and contains five different groups of plants or genera in our area. Most members have double serrate margins on the leaves. All produce catkins, but unlike their near relatives the Willows and Poplars, both male and female parts are on the same tree.

We might as well start with the genus the family is named after. Betula papyrifera, commonly known as White Birch. This is a species of the Northern Hardwood region. It's associated with Eastern Hemlock, White Cedar, White Pine, and Yellow Birch. White Birch is rare in Ohio, found only in a couple counties around Lake Erie. Birch bark is waterproof, and can be used to write on in place of paper. Sections were often cut and glued with balsam onto canoes. The other common names for this species is Canoe or Paper Birch.

All birches produce tightly packed fruit shaped like this. In time they will break apart into tiny winged nutlets. This species with the very elongated leaf tips is Gray Birch, Betula populifolia. Gray Birch can be found in several N.E. counties of Ohio.

Black Birch, Betula lenta, is also uncommon in Ohio, being scattered throughout the eastern part of the state. The leaves are narrowly egg shaped, and the double serrations are obvious. Because these leaves look identical to yellow birch, always check the bark.

Black Birch bark does NOT peel like other birches. It is dark in appearance, and often cracks open. They resemble young Cherry trees, and another common name is Cherry Birch.

Yellow Birch, Betula alleghaniensis. The range of Yellow Birch pretty much overlaps that of Black Birch in Ohio. Since the leaves look alike with these two, once again, check the bark.

Both Yellow and Black Birch have a shiny bark when young, but Yellow Birch will show more yellowish-green. With age, Yellow Birch will peel like a duck tail, or as if a wood planer had been run over the surface. Break the twig of either of these two species during the growing season, and you will smell a sweet wintergreen odor. Birch Beer has been made from these trees.

Dwarf Birch, Betula pumila. This is a small species, growing more like a shrub than a tree. The leaves are round, and the margins have coarse teeth looking more single serrate rather than doubly serrate. Dwarf Birch is rare in the state, being restricted to fen and bog environments in a half dozen Ohio counties.

Here in southern Ohio, our most common species is River Birch, Betula nigra. Look for it it wet soils. You can see the older trees look very dark near the base, but upper portions and younger trees have an orange pink or salmon colored look as they peel.

Even trees only an inch in diameter begin to show the color and splitting of bark. River Birch leaves are like Yellow and Black, but with more distinct serrations, giving it a Christmas tree silhouette.

Notice the horizontal rows of white lenticles on the bark. This is typical of all the Birch family members, but this one is not a Birch. This is one of the Ironwoods. Because that name is used to describe two species, let's break them apart. This is a young Ostrya.

Ostrya virginiana, is also known as Hop-hornbeam. With age the bark appears to have been run through a paper shredder.

The common name comes from the clusters of fruit that resemble the Hops used to make beer. A click of the photo will show a close up of the fruit stalk. They contain detachable hairs that act like stinging nettle, so be careful when handling them.

Ostrya buds are round or torpedo shaped. The scales overlap in an alternate pattern. The bud scales also typically alternate between yellow and brown. Some populations may show all black buds.

Now look at the difference in these buds. Besides the color, the scales are stacked in rows. The bud itself is not round, but angled or pyramid shaped. This is the other ironwood species.

Carpinus caroliniana, known as Ironwood, Blue Beech, and American Hornbeam. No need for such common names, just look at the bark, very muscular. I much prefer the fourth common name, Musclewood. Both Carpinus and Ostrya have very hard wood. They were used for umbrella handles, canes, bows, wedges, and prying poles or early crowbars back in  the day.

These and the following species all have their own genus because the fruit is different. Musclewood fruit contains a small seed subtended by a three pronged leafy bract. The fruit, bark, and buds are discussed here because the leaves look the same between the two Ironwoods.

The leaves on this species are much broader than all the previous trees. This is American Hazelnut, Corylus americana. Hazel is a shrub. New growth twigs show these gland tipped hairs. This is a good identification character, but they easily break off when handled.

The catkins on Betula, Carpinus, and Ostrya, are usually concentrated at the ends of the twigs, and often in threes. On Hazelnut, they can be located anywhere, and often occur in long rows. In fall and winter theses yellow catkins are tightly wrapped. They can be straight or curled like a caterpillar.

Come spring they soften up and become elongated. The catkins in this family are all male. They release their pollen, and the wind carries it to the female flower.

And here is what she looks like. Popping out of a bud scale is a magenta, spider like flower without petals.

Upon fertilization, a cluster of green fruit begin to grow, surrounded by leaf like bracts.

At maturity, you have our own version of a Filbert's Nut. These are just as edible, and are also sought after by wildlife.

It's the color purple, call Oprah. You don't come across purple buds very often, let alone those that are stalked. That brings us to the last members of the family, the Alders. We have two species here, the native Smooth or Common Alder, Alnus serrulata, and the introduced European Black Alder, Alnus glutinosa.

At the risk of repeating myself, Alders are in their own genus too because the fruits are different. They look like little pine cones. The fruit appears the same with both species. The leaves are widely egg shaped and end in a blunt tip.

Like the buds, the catkins are also purple. Buds, fruit, and catkins are similar between both species. Look to other characters to split them.

First, not all of the Black Alder leaves come to a point. Many of them have U shaped tips, like a bite had been chewed out of the top. Alders have nitrogen fixing bacteria on the roots, so Black is planted a lot in reclamation projects. It does not appear to be invasive.

Second, look at the bark. European Black Alder has not been with us for a long time. So I have never found much in any text that discusses the difference other than the leaves. What I have found is that Black Alder will grow straight and tall into a small tree. The bark stays black, and the horizontal lenticles remain visible.

Smooth Alder is a bushy plant growing as a shrub. With age the bark becomes gray and resembles Musclewood.

A Thorny Situation

Those woody plants that scratch and pierce our skin when hiking are often called some pretty colorful things by people. I will avoid such language, and describe exactly what they are running into. These "thorns" of Autumn Olive, Elaeagnus umbellata, are often referred to as branching spurs. This means they are not true thorns, just sharp twigs.

Wild Crabapple, Pyrus coronaria, is another plant with what we call "false thorns". If you feel a thorn that is bumpy, then it's just a pointed twig. Thorns will be smooth.

American Holly, Ilex opaca, is often described as having thorny leaves. They are not thorns, but spines along the leaf margin.

Another group of thorny plants are the Rubus. This is Raspberry. All of our plants around here have this white glaucous coating, so you don't even need to look at the thorns for identification.

Other piercing Rubus plants are the Blackberries. If you cut the twig and look at the cross section, they are star shaped. Blackberries have five sided twigs.

Blackberry and Raspberry are also plants that don't have true thorns. They are called prickles. So what is the difference? Generally speaking, prickles are just outward growths of the bark. True thorns are different tissue that grows out from under the bark. Spines are usually associated in some manner with leaves.

Who hasn't experienced some of the worst prickles of all. These curved fish hooks or shark fins belong to the notorious Multi-flora Rose, Rosa multiflora.

Our native roses can be just as detrimental. Swamp Rose for one, or in this example, the Climbing Rose, Rosa setigera. All portions may have tons of prickles. The problem with prickles versus thorns, is these have a bad habit of dislodging into your skin, ouch!

The Wild or Carolina Rose, Rosa carolina, is more of a minor annoyance than a major pain. Look for this Rose in dry upland woods. It only grows 1-3 feet tall. In the upper portions, the prickles are paired. In the lower parts they are thin and bristly. Most often they are colored white.

Greenbrier vines also have prickles rather than thorns. This is Sawbrier, Smilax rotundifolia. Sawbrier has square twigs and multicolored prickles that often look like candy corn. Sawbrier prickles are stiff and rigid and will pierce your clothes. This plant can climb on itself and form shrub like thickets. Avoid the "brier patch".  (Brier can be spelled with an a as well as e).

A second species of Smilax is Glaucous Greenbrier, Smilax glauca. The twigs are round and more brownish green than Sawbrier. The prickles are more uniform in color, and more numerous at the bottom of the plant. The twigs may or may not have a white coating in winter.

Our third woody species is Bristly Greenbrier, Smilax tamnoides (hispida). It only takes a second to see the main character for identification. The upper portions of the plant may be completely thornless, but look on down to the base. I mentioned Glaucous may have the majority of its prickles at the bottom, and they may be all black, but they are all the same size. Bristly has black "needles" of all different sizes.

If you thought Bristly looked intimidating, this is even worse. These are actual thorns growing up the stem of Gooseberry or Currant. This was taken on a spring morning in Iowa. The forest understories are covered with Gooseberry out there. This is probably Prickly Gooseberry Ribes cynosbati. Gooseberry fruits are very edible. The fruit on this species is spiny, making harvesting a bit tricky.

In the past, people raising White Pine removed all Gooseberries from an area because it spreads a fungus rust that kills the trees. While there are always exceptions, those Ribes called Gooseberries usually have thorns, and those called Currants are thornless.

Looking at the stems of this plant, it is similar to Bristly Greenbrier. The leaves though look more like a Locust. Let's try Bristly Locust, Robinia hispida. The red thorns here are actually hairs, and they extend up even onto the flowers. There are sharp spines between the leaflets. Bristly Locust is a southern species often planted in Ohio as an ornamental.

Robinia pseudoacacia, the Black Locust, is the more common species in our area. The twigs are hairless, but each node contains short paired thorns. Again, technically they're spines.

Less frequently seen in our area is a Black Locust look-a-like. With short paired thorns and compound leaves, it may be overlooked. This is Northern Prickly-ash, Zanthoxylum americanum.

One way to separate it from Locust is to look between the leaflets. They have a spiny rachis.

Up close the buds are fuzzy and bright red. It's also called the Toothache Tree. Like aspirin, it is said if you cut a slice of the bark or thorns, it deadens pain in the mouth. Personally I'd use the bark, but I don't think I'd put a thorn in my mouth.

There are so many varieties in this group, the thorns can be long or short, straight or curved. Either way, these belong to the Hawthorn, Crataegus spp. I don't really try to figure out which are which. No matter what the keys say, many of these turn out to be genetically the same species.

These round red buds remind you what your finger tips will look like if you get jabbed by a Hawthorn.

Japanese Barberry, Berberis thunbergii. Its bright red fruit make this an attractive ornamental, but is has escaped and become highly invasive. The leaves are small and spoon shaped. They grow out in clusters, though the plant is actually alternate. The long skinny projections are referred to as thorns, prickles, or spines. The literature is split on what to really call them. I lean towards spines.

To be sure you have a Barberry, take your knife and scrape the bark. The inner portions are a bright neon yellow.

A favorite of mine is Aralia spinosa. Sometimes called Hercule's Club, I much prefer the other common name, the Devil's Walking Stick. The thorns, which again are really prickles, often come out in a circular pattern, much like the Statue of Liberty Crown. In our area, look for it in the Hocking Hills region.

Elvis has left the building. So who is the current king? Without a doubt it has to be Honey Locust, Gleditsia triacanthos. Not only does it have thorns on the branches and trunk, but the thorns have thorns! They are multi-branching, and I have measured some 18 inches long. This is not something you want to get impaled upon.

I tell students to remember the latin name tri-acanthos by looking at the young thorns, they are branched into threes. They start out looking purple-red, and darken with age. I've also told students the thorns are toxic.

My choice of words may be misleading. They don't contain a liquid toxin or poison. The thorns may be covered in dirt or bacteria. These thorns are longer and more rigid than any of the other species mentioned. So when they pierce the skin, the wound is larger and deeper. It not only affects the skin, but can irritate the nerves. Major swelling can occur and last a week. Anti-inflammatories may be needed.

Honey Locust thorns have been used historically as sewing needles and fish hooks. The pea pods are sweet and edible when they first come out, not so later in the season. Black Locust pods on the other hand ARE poisonous. Don't eat those. At the risk of bursting your bubble again, Honey Locust thorns are not thorns at all, but spines.