The Buckeye Battle Cry revisited

Species name: Aesculus glabra

Common name: Ohio buckeye

Location: Western University campus

I know I've written a blog about the Ohio buckeye before (you can read my previous blog post HERE), but I wanted to blog about it again but with better pictures. And you know what? I'm allowed, because it's my blog :) So there!

The Ohio buckeye is a native species (well, marginally native. Definitely native to the northeastern United States; debatable whether or not it's native to southwestern Ontario) that does very well in full sun to partial shade. It's a medium-to-small tree in this part of Ontario because it's growing in a suboptimal part of its range, but further south into Ohio and Kentucky it can be a medium sized tree (up to 25 meters tall). The roots of these trees can tolerate intense rain and can tolerate temporary flooding, but do best in well-drained soil. There are some clear disadvantages to growing the Ohio buckeye as an ornamental species, and the first should be obvious: the fruit produced. If you're trying to increase the squirrel population, growing buckeyes in your yard is one of the best things you could possibly do. You don't want to come between a hungry squirrel and a buckeye tree! If, however, you have a lawnmower that you appreciate using and not replacing the blade every time you cut the lawn, you might want to reconsider this species. The fruits produced are enormous (in ideal conditions, some are almost the size of baseballs!), and when they split open they release one to three seeds. The seeds are large, hard, and really hurt when they hit you in the head. They do make fantastic ornaments, and are really stunning in flower arrangements. You can also collect the seeds and dry them to make beads, as is popular to do at Ohio State University. I can imagine they would be good for building neck muscles because they're so heavy, although I'm not sure why you would want to build your neck muscles.

Something that is often believed about the buckeye is that it produces inhibitory chemicals from the roots to prevent the growth of other species (called allelopathy) like in Norway maples and, to some extent, black walnuts. Fortunately, this isn't the case. To date there's no evidence that buckeyes produce allelopathic chemicals from their roots. Unfortunately, that doesn't mean that anything will grow under them! The canopy cover of buckeyes is just so dense that even shade-tolerant grass has a really hard time growing under buckeye trees. The best thing to plant under them would be highly shade tolerant ground cover, but even that might not do it in the long run. But the trade-off? Look at the trees! They're spectacular in their own right. They also turn bright orange early in the fall (late summer, really), long before other species start to change colour. And who doesn't love a bright orange tree in a sea of green?!

So how did the buckeye get to be so closely associated with Ohio? Well, there's the obvious reason that Ohio is the middle of the range for the buckeye, but that in its own right rarely causes a plant to be so ingrained in a state's culture. The story goes that Colonel Ebenezer Sproat arrived in what is now the United States in 1788 to command the Northwest Territory. Once he landed, the Indigenous peoples called Colonel Sproat "Hetuck" because they were so greatly impressed by him; he showed the native people immense respect and communicated with them instead of at them (as so many others did, and, to some extent, continue to do). To Indigenous North Americans, hetuck means the "eye of the buck" which shows power, respect and knowledge. I guess being called the eye of the buck is a great honour! He eventually became known as the "Big Buckeye" and all of the citizens under his control were his buckeyes. Eventually it became a term associated with all of those from and living in Ohio. The common name of the buckeye also stems from the fact that the seeds (or the "nuts") of the tree also resemble the eyes of deer. I bet you'll never look at a buckeye seed the same way again!

Should you decide to try to grow your own buckeye, make sure you find some nice plump seeds before they fall out of the fruit. They are very, very sensitive to drying and won't germinate if the seeds dry out too much. The best way to get around this is to find a fruit that has split open but has not yet dropped the seeds and take them home and put right in the ground. They won't germinate until the next spring, but there's usually a pretty good success rate. Plant a few, then pull all but a couple out of the ground in the summer. At the end of the next summer, choose your favourite and pull all of them but that one out (or leave a bunch! Nothing wrong with wanting a few buckeyes). Just keep in mind that you can't grow these indoors before transplanting (at least, not easily); they do require a period of exposure to extreme cold during the winter in order to germinate properly in the spring. Oh, and invest in a good rake ;)

The tree of anything-but-heaven

Species name: Ailanthus altissima

Common name: Tree of Heaven

Location: Ontario

Unfortunately, there are a couple pretty impressive specimens of the Tree of Heaven on campus, and this is only going to lead to disaster in a few years. The Tree of Heaven is a highly invasive species in North America, spreading underground via rhizomes and producing suckers that grow quite vigorously and grow in girth very quickly. This can not only be a menace to lawnmowers if this plant is in a decorative location, but they harbour a nasty secret underground. The Tree of Heaven produces some of the most toxic natural herbicides known, which successfully kill off any vegetation growing near them. While they don't seem to produce these chemicals in great numbers directly around their root system (other plants that aren't grasses can live happily in their shade if they are shade tolerant), they are produced in large amounts from the rhizomes to protect the developing suckers. This double-whammy of colonization and making the soil toxic to other organisms allows for their success at complete dominance over an ecosystem. They also thrive in disturbed areas where other species are slow to establish, also contributing to their success as an invasive species.

If you needed another reason not to plant this tree, it reeks. And I mean it smells TERRIBLE. The Chinese (the tree is native to China) even have their own traditional name for the tree: chouchun. Roughly translated, this means "malodorous tree." Other English names for this tree is the ghetto palm (not entirely sure how it got this name, but I kind of like it...) and the stinking tree. The odor probably has to do with the allelopathic compounds produced from the rhizomes; the suckers are especially disgusting after being "decapitated" with a lawnmower. It's almost enough to make you not want to go outside for fear of being drowned in their stench. On the bright side, this tree rarely lives past 50 years, so if you've got one in your yard you might want to remove it before it falls on your house.

Despite the incredibly foul smell produced from these trees, they are incredibly important in Traditional Chinese Medicine, where almost the entire plant is used for various purposes. A word of warning; this plant is toxic to humans as well as all other animal life so extreme caution should be exerted should you decide to go the TCM route. The bark is made into an astringent to treat a wide variety of diseases and disorders, from intestinal hemorrhaging to dysentery. There is also a significant amount of chemicals that are similar to quinones in the bark, and quinone is the most important antimalarial drug in the world. The drug-resistant malaria (or multi-drug resistant malaria) seems to still show strong effects of susceptibility to the ailanthone in the bark of the Tree of Heaven, and so is now a recognized antimalarial drug. The fruit of the tree when made into a tincture that effectively treats a vaginal infection called trichomoniasis, an infection caused by a protozoan that can be very difficult to treat. It is now the leading treatment for the infection by both doctors practicing Traditional Chinese Medicine and by doctors practicing Western medicine. It has also been suggested that this same medication will also have some effect on cancerous cells, but this has never been substantiated with clinical evidence. Extracts from the tree also have very potent anti-inflammatory effects, and have been shown to be incredibly effective at resolving severe allergic reactions (known as anaphylaxis).

The blackest of the walnuts

Species name: Juglans nigra

Common name: Black walnut

Location: Ontario

This tree was once incredibly rare in Canada, but now is starting to bounce back in population numbers due to the planting of ornamental specimens. The black walnut is native to the Carolinian Forest, which extends from the Carolinas northward to southwestern Ontario. The black walnut is now relatively common in British Columbia for its attractiveness as an ornamental species, but also its value as a lumber tree.

Black walnut has been used for centuries as one of the most valuable lumber trees in North America. Since these trees have one main trunk (unlike many oak species which tend to fork after about 40 or 50 years) that is usually incredibly straight, they make very long boards suitable for furniture building. At one time, walnut was even used as a siding for houses and as material to build decks. Not a smart use since it isn't as resistant to decay like a gymnosperm wood would be (like pine or cedar), and incredibly expensive! Since the grain and colour of the wood is so attractive, the wood is so easily worked, and the wood is not very likely to bend or warp when used indoors, the prices for black walnut wood soared in the late 1800s and early 1900s. Getting a piece of furniture made of solid walnut is rare today, and would cost thousands of dollars. It is much more common to have furniture made out of a wood like oak (or, worse yet, particleboard or plywood) and either veneered or stained to look like walnut. Sometimes, too, only the exterior parts of a piece of furniture will be made out of walnut, and all of the "guts" of the piece, the parts you can't see, will be made out of a much cheaper wood.

The black walnut is a great example of a tree with a compound leaf. It is by far not the most impressive example, either in Canada or around the world, but it has a very distinctive leaf that is easily identified. If you look at the third picture down, you can see where the petiole of the leaf (the green "leaf stalk" onto which all of the leaflets are attached) is swollen at the base and wraps almost all the way around the branch that it's attached to. There is a very similar and closely related species of tree in Canada, the butternut (also called the white walnut) that has one major characteristic of the leaves that is different from the black walnut. If you look at the end of the leaf, you'll notice that there's no terminal leaflet in the black walnut (sometimes there is, but it is never the same size as the rest of the leaflets). The butternut always has a terminal leaflet, and it's always at least the same size (sometimes bigger) as the rest of the leaflets.

Yes, the walnuts you buy at the store are the fruit of this tree! The best way to harvest them is to pull them off the tree when the fruit is still green and unripe since that's when the flesh on the inside tastes best. The green outer husk is incredibly difficult to remove (just sit and listen to a squirrel trying to get inside a walnut!), and the best and easiest way is to run over the fruit with an SUV. I'm not kidding! Line them up on the driveway or in a parking lot, and give it a go! Once the outer husk is removed, the nut on the inside (with the hard shell that's sold in grocery stores as "in-shell walnuts") will start to look familiar. Take a nut-craker, crack open the outer shell and enjoy! They don't need to be roasted in the oven first, but some people enjoy them more that way. Unfortunately, what's sold most often in grocery stores is the Persian walnut which is much easier to harvest (and probably accounts for its higher popularity). This is causing more and more Persian walnut trees to be planted in favour of the native species, which is always a downside of agriculture! A word of caution: if you're going to harvest your own black walnut nuts, make sure you wear gloves! Anyone who has seen the remnants of squirrels gnawing their way through a walnut on the sidewalk knows just how potent the dye from the husk, made up of juglone, plumbagin and tannins, can be! It will permanently dye your hands for weeks, and was actually often used as a permanent hair dye (and sometimes still is in "natural beauty products").

One downside of having black walnut in your yard is the fact that walnuts produce juglone in all of their tissues, including the roots. This chemical prevents the growth of most species of plants (and is incredibly toxic to some animals), so under most black walnut trees is a "dead zone" where nothing grows. This chemical is so potent that even black walnut seedlings, who can produce the chemical themselves, are sensitive to it and will die! This phenomenon is referred to as allelopathy, and one of the species I've already talked about, Norway Maple, is another good example of an allelopathic plant. Another good reason to wear gloves when harvesting walnuts is that some people are sensitive to juglone on their skin and it can cause an itchy rash (but the rash doesn't last as long as the dye on your hands does!).