BLOG RERUN: Dr. Jane Bowles, a great botanist, friend and mentor

This blog post was originally posted on July 30th, 2013 in memory of Dr. Jane Bowles, the Herbarium Curator and Director of the Arboretum at Western University in London, Ontario. There are very few weeks that go by that I don't think of Jane, and I've even caught myself thinking "I have no idea what this plant is; I'll ask Jane when she gets back" like she's only out for coffee or something. Gone too fast and too young; I don't think I'm alone when I say she is dearly missed.

Species name: Acacia tortilis

Common name: umbrella acacia, Israeli babool (in Swahili: mgunga, mugumba or munga)

Location: all photos from Dave's Garden (photo 1 by DMersh, photo 2 by DMersh, and photo 3 by palmbob)

You might be wondering why I'm featuring this plant in my blog today; for a full explanation you can scroll down to the bottom of this blog post past the next plant profile. Umbrella acacia trees are probably one of the first plants that come to mind when you think of Africa. They are for me at least! They have an enormous native range, reaching from the north all the way to the south of Africa and into the Middle East. When I think of the African savannah, this is by far the first tree (and sometimes the only tree; I'll be the first to admit that my African botany knowledge is quite limited!) that comes to mind.

The umbrella acacia actually looks rarely like an umbrella when grown in cultivation. Because it is so extremely drought tolerant, it is often grown in climates where the type of ecosystem that prevails for most of the year is a dry, sandy desert. Here, the umbrella acacia looks more like an acacia with a bad hair day, and is very straggly and wiry. It is only when the young seedlings are exposed to large amounts of rain that the trees end up developing into the typical umbrella-shape that is so characteristic of the African savannah. That, and grazing animals that force the tree into that shape couldn't hurt; this tree is one of the preferred food sources of giraffes. The "umbrella" of the canopy begins where the branches are just out of reach from the giraffes and everything below that point is eaten away. That's not the only animal that eats the umbrella acacia: humans have also used this tree as a source of gum arabic (added to many, many food items), and the seed pods are used for various herbal medicines. The seeds may be eaten by humans but are rich in tannins so are usually avoided (but may be used as a source of natural dye instead!), however other grazing animals like small mammals or birds eat these seeds as a rich (and rare) source of protein and fat.

There are quite a few products made from the wood of this tree, and is one of the reasons why it is grown so much in cultivation in Africa and the Middle East. The wood is very important for fine woodworking products like wagon wheels and furniture, as well as raw lumber for fenceposts and animal pens. The tabernacle, built by Israelites in the Old Testament, was also exclusively built from wood of the umbrella acacia so it has important religious significance as well. It also has very high significance to more than 20 different groups of people (either groups defined by language, linguistic dialects, country lines, or cultural beliefs), but the most important of which for the purposes of this blog post is that it's the National Tree of Kenya.

Species name: Stylophorum diphyllum

Common name: wood poppy, Celandine poppy

Location: Dave's Garden -- DaylilySLP

I think this is probably the only critically endangered wildflower species that I've ever personally seen in Ontario. When I saw it I didn't realize what it was or how important it was, so I didn't bother photographing it despite having my camera with me. Next time! There are only three populations in Ontario, which is the most northern part of its native range (which extends into the United States and is still quite limited; it is now only a small fragment of what it used to be), ranging in population size from 42 individual plants to about 270 individual plants (at last reassessment in 2007). It is a victim of land use change (converting forests to agricultural land) and invasive understory species (like garlic mustard, which you can read all about HERE), which continue to threaten the last three populations in Canada.

Wood poppies are similar to bloodroot, another native species which grows on the forest floor in southwestern Ontario (which you can read all about HERE), in that they produce a rhizome in their first year of growth, and use the sugars stored in that rhizome to produce leaves every spring. The rhizome of one plant isn't nearly as long-lived as in bloodroot, with the lifespan of the average rhizome only being about 5 years. The plant rarely produces flowers in its first year of growth (except in cultivation; it has become a popular garden plant over the last decade or so), so it is sometimes mistaken for other wildflower species during that first year. The seed pods that the plant produces are very unusual and are far larger than you would expect from a plant as small as this one (rarely growing more than 20 cm off the ground) and also share seed characteristics with bloodroot. The seeds are produced with a fleshy, fatty outer covering called an elaiosome which attracts ants. The ants take the small seeds and carry them away to their underground chambers where they use the elaiosome as a rich food source, then discard the seeds when they are finished. The seeds then germinate the next spring and grow up through the ground to produce new plants. This ant-plant dispersal relationship is called myrmecochory. Other animals, if given the chance, will also consume the seeds (seeds were found in great numbers in mouse droppings near one of the remaining populations in Ontario).

Medicinally, despite having close relatives that produce morphine and codeine, this plant has no value. It does contain some alkaloids that may prove useful in some medicinal sense in the future, but right now there is no documented medical use of this plant either currently or historically as an Native North American herbal medicine. The alkaloid cocktail in the plant is more than likely toxic to humans, so avoiding grazing on the leaves if you grow this plant in your garden would be strongly suggested. Wearing gloves when gardening around this plant is also suggested, as the sap from the plant may irritate sensitive skin.

Unfortunately, the fact that this plant is now grown in cultivation and the source of these plants is not a native source (which is actually a good thing; wild-harvesting of this plant in Canada is illegal and would be extremely detrimental to the few plants left in the wild) means there is now the risk of genetically contaminating the remaining plants. The populations in Canada had their DNA sequenced and compared to the US populations and it was shown that these three populations are genetically distinct from their American counterparts. This doesn't mean there was enough difference for them to be considered different species, but there was enough of a difference for it to be noteworthy. When the pollen of a foreign population mixes with the ova of a native population to make seeds, the foreign DNA from the pollen contaminates the native population, effectively creating "genetic hybrids" of both populations. Since plants in cultivation are usually much more susceptible to disease than their wild counterparts, this could be really bad news for our last three native populations.

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So why these two plants, you might be wondering? Well, these were the two plants I could best think of to commemorate the loss of a great botanist, my friend and mentor, Dr. Jane M. Bowles.

Jane grew up in Kenya, and some of the stories she shared about her childhood there are out of this world and beyond belief for someone that has lived in Canada their whole life (can you imagine growing up with a lion living in your front yard?! Mind-boggling to me!). She went to school in England, then moved to Canada to complete her PhD in botany about sand dune ecology at Pinery Provincial Park. Since the completion of her PhD, Jane was an adjunct professor in both Biology and Geography at Western and, most recently, the curator of the herbarium and the director of the arboretum.

I first met Jane at the field station associated with Western when I was out there with my supervisor searching for fungi in the woodlot at the back of the property. My supervisor introduced Jane as the curator of the herbarium (assuming I knew what a herbarium was; I was thinking "herbari-what?!"), and we went on our merry way. It wasn't until a couple of months later that I realized that, aside from my supervisor, Jane would probably be the single most important person (well, aside from myself, too, obviously) involved in the successful completion of my PhD. I rely so heavily on herbarium loans to look at historical mushroom specimens that I would have been completely lost without her. Not to mention that Jane was universally loved and respected by all herbarium curators around the world; with her as my primary source of communication to other herbaria I would have no problem having a loan in my possession two, three, sometimes four times longer than the period of time I was actually given. If you think that's bad it's not; it's not unheard of to have herbarium loans for 10 years or more!

Over the last 6 years I would say that Jane and I had become friends. I always knew I could count on her to provide me with a laugh thanks to her biting sense of humour, I could count on her for a swift kick in the bum to get myself in gear when I asked for it, and give me some helpful tips on how not to lose my sanity along the way. I would also say that her love for plants inspired me to grow to love them (sorry for the pun...actually, not sorry. That was carefully planned!), too. She taught me about the importance of native species, and drilled into my head the dangers of invasive non-native species. She opened my eyes to a whole new world of Biology: being a naturalist, and helping preserve the world for what it currently is and not try to change it to be what we want it to become to "improve our life" (it's often too late when we realize that having a giant forest was perhaps a bit better than yet another strip mall...).

Earlier this year, Jane was diagnosed with cancer. On Saturday, July 27th 2013, Jane lost her fight at Victoria Hospital. There won't be a day that goes by where I won't think of her, not a week that goes by during the rest of my time at Western that I won't remember one of her tidbits she told me, and not a year that goes by where I won't be reminded of what an amazing lady Jane was.

Goodbye, Jane. May your memory live on, and may you continue to inspire young impressionable scientists such as myself to become one with nature forever.

Jane was known for her amazing artistic abilities; this is one of her drawings 

of the wood poppy, which she drew for her co-authored species status report 

(you can read the most recent version HERE)

The chestnut that horses don't want

Species name: Aesculus hippocastanum

Common name: horse chestnut

Location: Western University campus

The horse chestnut is a tree native to southern Europe around the Mediterranean and the Balkan Mountains. While the native range of this species is actually quite small, it is one of the dominant species that exists there and is also widely planted around the world. It can be a pretty nasty species (more on that below), but has a stunning flower display in late April and early May. The fruits, looking very similar to the fruits of the Ohio buckeye (which you can read all about HERE), start to appear in late summer. They are mostly left alone, but can be eaten (and seem to be enjoyed) by deer.

The common name of this plant is incredibly misleading, but is based in history. First the "horse" part refers to an anecdotal story that after horses ate the fruit, they would no longer complain of chest pain. You'd have to be some sort of pretty awesome horse-whisperer to be able to have a horse tell you it no longer had chest pain! The other minor detail to this story...you wouldn't be able to hear the horse telling you "Thanks! My chest pain is gone!" over the sounds of its seizures. Horse chestnut seeds and the fruit walls are poisonous to horses and should never be fed to them under any circumstances. Horses are pretty smart animals; they won't touch them. The other half of the name comes from the fact that it was believed that this tree was closely related to the American chestnut tree, mostly due to the fact that they have similar fruit and seed appearances. The leaves, however, are wildly different and the flowers of the true chestnut trees are also not nearly as showy. They are not easily confused, nor are they closely related! The true chestnuts and the horse chestnut are only distantly related.

The uses of the horse chestnut are so varied it makes me wonder if this really is a "miracle tree". The first use I'm just going to do the ultimate "thou shalt not do" and just copy-paste from the horse chestnut Wikipedia article because it's so mind-boggling. Here it is:
"In the past, horse-chestnut seeds were used in France and Switzerland for whitening hemp, flax, silk and wool. They contain a soapy juice, fit for washing of linens and stuffs, for milling of caps and stockings, etc., and for fulling of cloth. For this, 20 horse-chestnut seeds were sufficient for six litres of water. They were peeled then rasped, or dried and ground in a malt or other mill. The water must be soft, either rain or river water; hard well water will not work. The nuts are then steeped in cold water, which soon becomes frothy, as with soap, and then turns milky white. The liquid must be stirred well at first, and then, after standing to settle, strained or poured off clear. Linen washed in this liquid, and afterwards rinsed in clear running water, takes on an agreeable light sky-blue colour. It takes spots out of both linen and wool, and never damages or injures the cloth."
That is...crazy. How is this not marketed as a product?! A "natural" way to clean wool and linen, and the fibres are not destroyed in the process. The only thing I can figure is that it must be prepared fresh each time, and so it's viable today as a marketable product. If it was, it could be turned into a "Tide Stick type of product"--a Wool Stick?--and sold as a spot cleaner. This could be quite the money-maker...

The second historical use of the plant is as a soap and shampoo, along the same lines as the first use. The seeds are ground into boiling water in a sealable container (which sounds like a disaster waiting to happen, but what do I know?!), shaken vigorously (try not to have the container explode on you...), and then strained. Once the liquid is cool enough to be applied to the scalp, it works to remove the buildup from your hair. Nifty! Not nifty enough for me personally to want to try it, but nifty all the same.

Along a totally different vein, the seeds of the horse chestnut can also be broken into small pieces and then added to a fermentation solution containing the bacterium Clostridium acetobutylicum, from the same genus of bacteria that gives us botulism which is a very potent type of food poisoning, which produces acetone as an end product of fermentation (instead of the usual ethanol like brewer's yeast produces). Acetone can then be diluted to make nail polish remover, or it could be used later in the production of cordite (it's first use, prior to nail polish remover), an explosive used in bombs (and as a gunpowder replacement in other explosive devices like bullets).

And yet another completely different use, in order for an outdoor patio to be called a true "beer garden," it must be shaded by horse chestnuts according to Bavarian law. Now the term applies to any outdoor patio space where beer is the main item consumed, but that didn't used to be the case. Bavarian law also dictates (as an aside) the only four ingredients which may be used in the beer-making process: water, barley, hops, and yeast. If the "beer" that you drink contains anything other than those four ingredients (such as wheat beers, rice beers, or beers flavoured with things other than hops), it technically cannot be called beer.

One of the compounds found in horse chestnut seed extract, aescin, is used medicinally to treat a condition called chronic venous insufficiency or CVI. This condition arises when the veins can no longer return deoxygenated blood in your body back to your heart (where it pumps it to your lungs to push out the carbon dioxide and pick up new oxygen). This can result in severe pain due to a lack of oxygen in the extremities, and in especially severe cases can result in the loss of limbs. The causes of this condition can be quite varied, with specific medical conditions often arising in CVI (like diabetes, MS, and even a brief disruption of oxygen to a developing embryo in the womb) or the result of repeated leg injuries (like in the case of paratroopers, tree-climbers, mountain climbers, or people who climb utility poles for repairs). This is not a do-it-yourself medical treatment, however. The aescin must be carefully extracted from the seeds and purified in order to exclude any esculin, a deadly toxic glycoside also present in horse chestnut seeds, from the preparation. If even a small amount of esculin is ingested it can result in seizure, vomiting, severe dehydration, coma, and even death. Unfortunately, this doesn't stop homeopathic practitioners from prescribing it as a homeopathic remedy to thin the blood. Yet another example of the idea that just because it's natural doesn't mean it's good for you or even safe. Be aware of what you're putting in your body and the potential side effects!

The maple of Black Friday

Species name: Acer nigrum

Common name: black maple

Location: Western University campus

What better way to celebrate the phenomenon that is Black Friday with a...black maple! You bet I've been holding off on this blog for weeks! For those of you not from the United States or Canada and who are unfamiliar with this "Black Friday thing," here's a brief run-down. Traditionally in Canada the day after Christmas is called Boxing Day. Truly, I have no idea what the history of Boxing Day is, but now it has morphed into the National Day of Shopping. Crazy people (like me) get up at 6 am in order to make it to the mall as soon as it opens, and every store has some kind of crazy sale. Boxing Day is one of my favourite days of the year since I love shopping, but I absolutely refuse to pay full-price for an item. Not to be outdone, the United States has Black Friday. Since Christmas isn't actually that big of a deal in the US (trust me, I'm surprised, too), Thanksgiving is their biggest national holiday (aside from possibly Independence Day in some areas), and it weirdly occurs on a Thursday. In order to "bridge the gap" between Thanksgiving and the weekend, the phenomenon known as Black Friday has evolved. That is the day that Americans get up ridiculously early and go shopping. And let me tell you: Black Friday deals in some stores are ridiculous. While I've never been to the States on a Black Friday (and never intend to go; the day is notorious for people getting trampled to death in order to get to the good deals first), I've heard some great stories of people scoring big-screen TVs for $32, or a brand new iPhone 5C for $49 with no contract. That's crazy! I have no idea whether Boxing Day or Black Friday came first, but I like to think Boxing Day did. Because I'm Canadian, and all good things are Canadian before Americans steal our ideas. Like basketball. And hockey.

Back to plants! The black maple is actually a "species" under furious debate amongst botanists, and the crowd is currently split about its species status. There are some botanists (that I like to think are in the majority, but I'm honestly not sure) that say the black maple is a good species and deserves its own Latin name. There's another group, however, that is absolutely convinced that it's merely a subspecies of the sugar maple, and should actually be called Acer saccharum subsp. nigrum. Unfortunately, should this prove to be the case, the black maple would lose all designation as a species and no longer be protected by any kind of Species At Risk legislation across all of North America, where it has its native range. To me, this would be tragic since I happen to really like black maples. But I do see where "the other side" is coming from: black maples and sugar maples readily hybridize with each other, their wood can be used for the exact same purposes in the lumber trade because they have the same grain qualities and the same chemical makeup (the same amount of lignin and cellulose, with the same type of ring structure), they can both be used to produce maple syrup (although, black maples much less so than sugar maples), and they have very similar maple key characteristics. The most notable difference is the shape of the leaves; the black maple leaf is much more rounded at the bottom than the sugar maple (which is nearly flat), the black maple leaf has only three main lobes with no minor lobes (the sugar maple leaf has three main lobes and two much smaller lobes at the base near the petiole), and the leaves of the black maple "droop" like they're always slightly dehydrated (while sugar maple leaves are flat and not droopy at all). In fact, the slightly floppy quality to the leaves is the reason why most black maples are accidentally massacred on residential properties. Because they always look like they're drought-stressed and need water, people who don't know that's what black maples look like normally drown them to death. The poor trees! And I will admit, until a few months ago I would have been in the "drowning the tree" boat. I always thought this poor tree needed some water (and since it is in the middle of an island in a huge parking lot, not getting much water is a very real possibility) and so likely would have drowned it, too, had I not been told differently. Now we all know. :)

So what are black maples good for, aside from maple syrup? Well, a lot if you ask the Ojibwa people. Not only did they boil the sap of the black maple to concentrate the sugars to use as a sweetener in cooking, but they also boiled the bark and drank the resulting liquid to treat diarrhea and to act as a diuretic. Neither of these uses have been evaluated in clinical trials. The branches of this tree can also be very straight, and so made good wood for arrows and were the preferred source for "arrow wood". The wood of the black maple is also easily carved, especially when young, and so was sometimes carved into elaborate shapes for ornamental pieces and for kitchen items like spoons and bowls.

If you went out to brave the crowds today, hopefully you managed to pick up something you liked and got a great deal!

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 ;)

Sycamores: nature's ghosts in the woods

Species name: Platanus occidentalis

Common name: American sycamore, American planetree

Location: Western University campus

The American sycamore (just "sycamore" from here on out since I live in North America) is native to eastern North America and has quite an extensive range throughout the Carolinian forest (from Ontario south to Texas and Georgia and everywhere in between). Depending on the environment, it can be an absolutely enormous tree, reaching heights of 40 or 50 meters (sycamores are some of the easiest trees to spot from the edge of a forest, especially during the winter, because they reach above the rest of the forest canopy) and diameters as large as 4 meters. The largest sycamore ever recorded was in 1770 recorded by the one and only George Washington near the junction of the Kanawha and Ohio rivers; he recorded in his journal the tree was approximately 14 meters in circumference! Go measure out a piece of string 14 meters in length and go wrap it around the biggest tree you can find. I bet your "incredibly large tree" will be tiny in comparison to your string! This tree, for obvious reasons since trees don't live forever, is no longer standing but it's not uncommon for a sycamore to be 6 or 7 meters in circumference if rooted in deep soil.

Sycamores are spectacular trees to see, but especially during the winter. Some people call them the "ghosts of the forest", but not just because of the colour of their bark. The new growth of the tree is almost pure white, and that scaly brown bark develops near the base of the tree as the tree ages. The white bark is actually iridescent; when the moonlight shines on the forest and sycamores sway in the breeze, it almost looks like they're glowing and sparkling in the moonlight. It's pretty cool to see, but also a bit creepy. If you've ever had nightmares about sycamores coming to life and grabbing you off a trail while you're running from ghosts through the forest, this could be why! The brain does some mysterious things... :) The sycamore is an interesting study in the use of common names assigned to species, and how they differ with geography. If you're from North America, this tree, being in the genus Platanus, is a sycamore. If, however, you're in Europe (especially in Britain) trees in the genus Platanus are called planetrees. Seems simple enough. But the plot thickens. If you are calling a tree a "sycamore" in Europe, you're actually referring to a species of maple called Acer pseudoplatanus. And if you're referring to a planetree in North America, you're referring to the hybrid Platanus x acerifolia (to be profiled in the next blog). Ugh! Oh how I wish things were simpler...

So what's so special about sycamores? Well, they're relatively unique trees in that they're riparian or riverbank species, and at the same time they have incredibly weak root systems. How do I know that, without ever having seen a root system of a sycamore? Well...look at the trees. Next time you're walking along a stream or a river with sycamores growing, look at the shape of the trees. Chances are, none of them are straight up and down. This is because when the trees were young and growing along the bank of the river, the freeze-thaw (or extreme floods of the rainy season) cycles caused the damming of ice up against the trunk of the tree. The roots weren't strong enough to support the tree upright, so it started to lean the same direction that the ice was pushing. If you look at a mature sycamore, it still has the lean of the direction of the river or stream. Extreme flooding would do the same thing; it would wash away the soil near the base of the tree causing the trunk to shift, and lean the direction of water flow. If you see a sycamore growing out all by itself in a big farm field and it leans, chances are the farmer has reclaimed the land where the river or stream used to be and put pipes to drain away the water instead. That lone sycamore is the only remnant of the forest that used to be present.

There are two main uses of sycamore trees today. The first is as an ornamental wood for a very specific purpose: in butcher blocks. Many wooden cutting boards are also made out of sycamore wood. It is strong and very durable, with very coarse grain that shows a nice pattern when stained and sealed. The coarse grain makes it very difficult to work with, but is still sometimes used in constructing furniture. The other main use of the tree is as a biofuel crop, since initially it grows very quickly and accumulates a lot of carbon. The wood of the tree can be burned in an oxygen-poor environment to make charcoal, and then burned again for fuel. Not necessarily the cleanest method of energy generation, but certainly better than burning coal (and charcoal could be burned in many of the pre-existing coal plants, providing there was enough charcoal to make it worthwhile!).

Not named for its resemblance to a fish or a musical instrument: the basswood

Species name: Tilia americana

Common name: American basswood, American linden

Location: Western University campus

The American basswood (from now on I'll just call it the basswood, since I'm in one of the Americas) is a great native species that's tolerant of many environmental conditions naturally thrown at it in North America (from Ontario and Quebec all the way south to Nebraska and Tennessee, but some pocket populations even exist in Mexico!). It is highly drought-tolerant, is shade-tolerant, salt-tolerant, and even flood-tolerant. Unfortunately, this tree has largely been replaced in ornamental plantings by the littleleaf linden (or, if you'd like, the European basswood), Tilia cordata, because of the rather unruly growth of the basswood (you can read all about the littleleaf linden HERE).

What do I mean by unruly growth? Well, if you look at the first image that's not exactly the type of "specimen tree" you'd normally see on boulevards. Once this tree reaches a certain height, it's nearly impossible to stop it from starting its bushy growth. It naturally clones from the base of the tree, and suckers form at the base. If you catch them early they're easily removed with a pair of small hedge clippers. But because of their vigorous growth they can get very large very quickly. They can grow so fast, in fact, that it's sometimes difficult to determine which was the original stem and which are the suckers! There are a few varieties of the basswood that don't sucker, but early settlers in North America figured this tree was incredibly similar to the "lime tree" they grew back home, so they just brought their linden trees to North America. Now, you can find large linden trees planted along roadsides as ornamental trees.

If you look at the second and fourth photos, you can see a rather unique characteristic of the basswood that the littleleaf linden doesn't show, and that's that not all leaves are created equal. Since I didn't think to include an object for reference of scale (only realizing after the fact that this was a poor decision), I included scale bars for reference to measure the widths of the leaves. The second image above is of a canopy leaf, as evidenced by the fruit that can be seen growing (they do not grow on sucker shoots until they reach the canopy). The scale bar on that leaf corresponds to about 10 centimetres, or about 4 inches. That's a pretty average size for a leaf in the canopy, but the ones at the very top are slightly smaller (some in shaded areas near the trunk of the tree an also be slightly larger). The fourth picture is a leaf growing on a sucker, and the scale bar on that leaf is about 35 centimetres, or almost 14 inches. That's an absolutely enormous difference, and one that can be consistently seen in all basswood trees (so you don't have to worry that I chose a mutant tree!). So why the huge difference in leaf sizes? This phenomenon can actually be seen in many plants, but to a smaller extent: leaves changing sizes or shapes to be better competitors for light. The small leaves at the very top of the tree don't have to be very big to get lots of sunlight, because nothing is blocking them. In fact, many leaves at the tops of tree canopies are angled so only the edges are exposed directly to this sun which prevents them from getting sunburnt :) (this phenomenon is called "scorch" in plants and is common in plants grown outside of their native range) As you travel further down the trunk towards the ground, there is less and less sun that reaches the lower leaves. They must grow bigger, and are usually darker in colour, to be able to absorb more sunlight to make sugars. For something without a brain, basswoods are pretty smart!

Surprisingly enough, both the leaves and the fruits of this tree are edible to humans, although not all that pleasant. I can't say I've ever tried them, and I also can't say I'll be tempted to do so in the near future. That being said, if you get lost in a maple-beech hardwood forest and are looking for food, finding a basswood would be a nice source of vegetal munchies to sustain you for a few hours. The basswood has also been used as a medicinal plant for many centuries, having effects very similar to the littleleaf linden (which is arguably more potent). The leaves can be steeped in a tea and consumed as a treatment for cough, cold, flu, and indigestion (none of which have been demonstrated to be effective treatments according to modern scientific studies); the flowers can also be steeped for the same purposes but also as a diuretic to promote urine production, as a sedative, and as an antispasmodic to quell intestinal cramps; and even the wood is used (once burned to charcoal) as a treatment for lower leg ulcers, cellulitis, edema, or infection (again, none of these treatments have shown any promise in modern clinical trials). As an aside, rubbing burnt wood into an open wound in order to treat infection is probably not a smart idea. Wood is festering with microbes whether burnt or unburnt (it's amazing the types of bacteria and fungi that can grow on charcoal!), and in order to sterilize it you have to use it while it's hot; rubbing burning wood into an open wound will probably do more harm than good, and I'm sure you can imagine why!

Hackberries can be nature's lightning rods

Species name: Celtis occidentalis

Common name: common hackberry, northern hackberry

Location: Western University campus

To keep with our "super-massive-gigantosaur" trees on campus, I have a compilation of pictures of the two biggest hackberries. Actually, I might be wrong on that one. When I asked Jane back in June if these were the biggest hackberries, her response was "I think so." Because it wasn't an adamant "yes!," I can't be positive; I'll have to keep track of all of the really big hackberries on my wanderings around campus from now on to see if I can find a bigger one than this one.

Hackberries are trees that are native to the Carolinian forest, with their native range extending from Ontario and Quebec in Canada south to Tennessee in the United States. It still exists in moderate numbers, but has a low tolerance to disturbance so is often one of the first species lost from a forest after a clearcut (even though there are seeds that are still in the seed bank). That being said, they are very good urban trees, and can withstand quite a bit of air pollution with no ill effects. The berries on the tree, which you can see in the third, fourth, fifth and sixth images above, are a great food source for native bird species preparing to migrate south in the fall, as they are some of the most nutritious berries available. They start off green on the tree then mature to a reddish-orange. At this point they can be picked by humans for consumption but be warned: "tart" is an understatement. I tried a bright red berry and thought my mouth was about to turn inside out from the sourness of the fruit! The way that hackberries are traditionally consumed by humans is as a jam or preserve-like substance: the berries are cooked in a simple syrup (equal parts sugar and water) until they are mushy. They can then be used exactly like cranberry sauce on meat! After turning red/orange on the tree they start to turn a dark purple-black, and this is what birds consume. This concentrates many of the sugars in the fruit to make it more energizing, but also concentrates other compounds that react not very nicely with the human digestive system. If eaten raw they can cause severe stomach upset (but nothing that would require a hospital visit unless a whole bucket were to be consumed!). Once they're black and wrinkly like the bottom picture they can be used in wines and beers as a fermentation product. They give the beverage a really fruity undertone that, from what I understand, is unusual and pleasant all at the same time. The good thing about hackberry trees is that the fruit that falls from the tree doesn't start to smell after sitting on your lawn after a while (the same cannot be said for apples, crabapples, cherries, Cornelian cherries, or plums!), and the spent fruit do not attract bees or wasps in large abundance. These trees do grow relatively quickly, so are a great possibility for a boulevard tree. The bark is also spectacular, and one of the characteristics of hackberries that can be used for proper identification even in the dead of winter. In very mature specimens where the bark is starting to peel off, you can soak the bark in water to plump it back up and carve cork-like plugs out of it to use as stoppers. A multi-function tree!

So how big is this tree? Well, it's pretty big. Not as large as the Burr oak from my last blog (which you can read HERE), but still pretty darn large. Here's the herbarium tag for reference:

If we use our same method of size estimation as last time, that tag is approximately 6 x 14 cm (or 2.5 x 5.5 inches). Using my "tag estimation method" (there are about 12 tags that could fit across the tree, so the diameter would be approximately 66 inches or 167.5 cm), the circumference of that tree is 207 inches (5.26 meters)! That's one big tree. But wait...didn't I say it wasn't as large as the Burr oak? Circumference-wise, it's definitely larger at the largest point. But what you'll see if you look closely at the shape of the tree, versus the shape of the big Burr oak, this tree tapers starting nearly at the bottom of the tree. The Burr oak is like a barrel, and only starts to narrow very near the top of the canopy. If you compare weight or total volume of the trunk of the tree, the Burr oak is much, MUCH larger. That being said, this hackberry still has quite a few years left to live (this one is probably "only" about 200 years old) so I'll have to come back to visit this tree every decade or so to see how long it lives and how much bigger it gets!

So what's so special about hackberries? Their berries aren't overly tasty (for humans at least), their wood is of terrible quality (as far as furniture-building goes; it's very brittle and has uneven grain so is only used in cheap fencing and cheap furniture) and isn't very decay-resistant, and they can get old. So far, not very exciting-sounding. Well let me tell you...hackberries can withstand a huge level of "unanticipated stress" and make it out unscathed. Most trees, especially established trees, could never tolerate being split in half and heal up just fine. Hackberries regularly do this. Here's an example:

That tree might not look like much (for size perspective, it's only about half the size of the tree pictured above), but it's a survivor of a really unusual phenomenon, and one that trees rarely recover from like it never happened: lightning strikes. If you click on the image to enlarge it, you'll see a big ridge running from a large wound about 5-10 feet off the ground that extends all the way up to the end of one of the tallest branches. The lightning likely struck the branch, and the electrical charge traveled down the tree until it found a way out; that might have been where a branch once was, or perhaps it was even just a crack in the bark from a burrowing beetle or woodpecker. The ridge, while nearly impossible to tell from the angle of the picture, extends all the way to the ground on the other side of this big hole in the tree. The fact that this tree was nearly split in half by a lightning strike and has since recovered like nothing ever happened is pretty telling to how resilient this species actually is. An absolutely remarkable feat. Makes me want a hackberry just to have it get struck by lightning. What a great story to be able to tell your grandkids, or even great-grandkids!