Wine? Wine not!

Species name: Vitis riparia

Common name: riverbank grape

Location: Western University campus

The riverbank grape is one of our great native vine species (the other major native eastern North American species to be featured in the next blog, Virginia creeper). It is a very vigorous grower, capable of growing up to the top of a riparian forest tree canopy (not nearly as tall as a "normal" tree canopy of a forest, since trees that live in riparian, or riverbank, areas don't tend to be able to grow as tall). In the southern areas of its native range it can be a real pest species, but here in Ontario other native species are pretty good at competing with it. Some trees have a harder time than others, but non-native species have an especially difficult time with the smothering tendencies this species sometimes has. That being said, as soon as it is transplanted, either naturally via bird poop (the most common animal vector) or "artificially" via human transplantation, into an area of lowland or upland forest the forest canopy can really suffer as a result. It is remarkably good at smothering new saplings before they have a chance to grow tall enough to escape it, and some forests are so thick with grape vines they're impassable. A great example of a species that grows well in harmony with other species in its native habitat, but can become a real pest, even in its native range, if introduced beyond those limits.

The riverbank grape has a bit of a bad rap in Ontario and the northeastern United States, but that perception seems to be changing a bit. In the 1940s and 1950s, the US government (the Canadian government quickly followed suit) decided that riverbank grape vines were a forest pest and that this species should be eradicated. There had been a lot of accidental introductions of this species into areas important in the logging and lumber trade, and if you're allowing a vine to smother your profits you're not a very good businessperson! So instead of just local eradication programs, these programs were carried out across the United States and into Ontario and Quebec, and whenever a riverbank grape vine was seen in a forest (either riparian area or otherwise) it was sprayed with very toxic herbicides. This was very effective at killing the vines, but also equally effective in killing all of the surrounding vegetation and poisoning the soil (both for soil microbes, very important in forest health, but also making it inhospitable to new seedlings). Unfortunately, it was far too late before anyone realized what was happening, so you still find "dead zones" where mature trees escaped the soil poisoning by having a root system vast enough to support itself with un-poisoned soil, but the understory species are completely missing. I have a rather personal connection to riverbank grape, because one of the species of fungi that I study for my PhD grows exclusively on grape vine in North America. Unfortunately, there's a catch (as there always seems to be with rules regarding where fungi are most likely to be found): it only grows on mature, living or dead grape vine. This means that any suitable habitat that might have been in forest ecosystems in the 1800s when a lot of the work was being done on the fungal flora of North America no longer exists for this species. For this reason, it was collected three times in the 1880s by great, now long-dead, mycologists only to never be recorded ever again. Have these species gone extinct because of our destruction of their host species? No one, including myself, knows that for sure. Since the 1930s there has been a lack of concerted effort to document the diversity of forest species, only re-invigorated in the early 2000s. What I can say is that for the last 6 years whenever I'm in a forest where there's grape vine I look for it...and haven't found it yet. Perhaps I'm not looking in the right spot, or perhaps it doesn't exist anymore. I'll let you know in 20 years when I either find it or give up looking. ;) This idea of "disappearing species" is not unique in mycology; there are also a lot of plant species that were discovered during the times of the Great World Explorers (as I like to call them) that have never been found again. Part of the problem stems from the lack of location data for the collections--how do I know where "Aunt Edna's House, near the south greenhouse but past the wood pile, 5 minutes from the beach" is?! Sure, maybe EVERYONE in 1872 knew where Aunt Edna's house was...but it's long gone by now. You don't realize just how useful GPS coordinates are until you have to figure out something like that!

Anyway, back on topic...

Riverbank grape fruits are reportedly edible, and were also reportedly an important food source in the summer for early settlers in North America. Now, I'm guessing that tastes have progressed a bit since those times, or perhaps they were much less picky eaters than we are now (or maybe a bit of both). Have you ever tried a grape from a wild grape vine? They are TERRIBLE. I wasn't expecting a sweet grape when I tried one, but holy jeez. This was...terrible. That's the only way I can describe it. It was gooey and had the most awful texture on the planet (almost like jello on the inside), plus one of the most sour fruits I've ever had in my life (puts the Cornelian cherry to shame, which you can read all about HERE, and I often eat lemons for fun...so that tells you something about my tolerance for "sour"). My friend Tanya convinced me to try one when we were out geocaching one afternoon, and I could taste the lingering "lip-puckering sour" in my mouth for hours. That's the last time I ever listen to Tanya. Ha.

Sure, the grapes don't taste that great and the plant isn't all that much to look at (although, I personally really love the shape of their leaves and the cute little curving tendrils that are most visible during the winter and early spring), riverbank grape is one of the single most important "novelty agriculture species" that we have in North America. I call them an agricultural novelty not because their use is new, but because the product we get from them is certainly not necessary for everyday life (some people might argue with me on that one; we'll agree to disagree) nor has it ever been. Wild grape vines are VERY tolerant to winter conditions in North America, which can be incredibly harsh, especially in the ground. Traditional wine grape vines, of the species Vitis vinifera, don't have a very cold hardy root system, and are prone to freezing damage in northern climates. For this reason, riverbank grape rootstock is often grafted onto a wine grape scion (or "top") for commercial grape production for the wine industry. Once grapevine producers were experts in the creation of natural hybrids, they started experimenting with different varieties of V. vinifera as well as V. riparia to make more cold-tolerant grape vines, but with the same commercial qualities of traditional wine grapes. Another major benefit is that the resulting hybrid is much more resistant to common fungal diseases encountered on grape vines. Eventually what was obtained were varieties that were genetically 50-80% wine grapes, and 20-50% riverbank grape. Baco Noir, Marchel Foch (sometimes called Marechal Foch) and Frontenac grapes are all hybrids between these two species, and produce some of the best wine in the world. Isn't it amazing what a little traditional plant breeding can do?! Cheers to grapes.

Traditional uses by Aboriginal North Americans are also numerous; they are used as a food (although, I'm guessing in small numbers), to make jellies and jams, and to produce a type of traditional North American wine. From what I understand, this wine is really unpleasant when compared to wine from a "real" winery, but it really packs a punch: it has 2-3 times the alcohol content of a traditional wine. Maybe it's alcoholic enough you don't realize how terrible it is! Not commercially sold, but every so often you might be able to find some courtesy of a backyard brewer. Let me know how it is, if you get a chance to try it.

Burr it's cold!

Species name: Arctium sp. (probably Arctium lappa)

Common name: burdock (probably greater burdock)

Location: Western University Campus, London, Ontario

I decided to start this year off with a bang, or a burr if you will, using a blog post with lots of pretty pictures. :) Who doesn't love pretty pictures?! The burdock plant is pretty well-known in North America where it was introduced from Europe, the Middle East and Asia (pretty much every area in the Northern Hemisphere EXCEPT North America). Across its native and introduced range it has the potential to become quite invasive, as it thrives in disturbed, nitrogen-rich soils. This makes it an especially-potent agricultural weed species. In most cases, however, when burdock seeds enter an area (especially a landscaped garden like you'd find around a home) a couple might develop into plants but spreading is rare. While I took these pictures on campus, there is also a very small colony (two plants) growing in my back yard. Since they're out of the way, I've left them there and hoped that the "keeper of the garden" (aka my dad) doesn't find them ugly enough to remove. To me, they're pretty in their own way. I wouldn't want lots of them (since they're irritating in their own way, too!), but one or two is just fine.

I had a bit of trouble getting this plant down to the species level because I neglected to make notes of (or take pictures of) the distinguishing characteristics between the greater burdock and the lesser burdock. One of the main ways to tell them apart is by looking at the base of the flower, or what we would call the "burr." If the flower is on a stalk, it's the greater burdock, and if the flower is directly attached to the branch (or is on a very short stalk), it's the lesser burdock. Since I think these pictures are just great, I'm going to go with the greater burdock :) Next time since I know what I'm looking for I'll make sure I photograph the stalks (or lack thereof) that the flowers are sitting on so I can make sure my identification is correct! There is one more burdock species in Ontario (also a non-native species) called the woolly burdock, but this one is easily distinguished from the other two. It has a bract at the bottom of each leaf that has very fine spike-like hairs on it. Neither of the other two species we have here show this characteristic. Aside from the flowers on (or not on) stalks, the other way to tell the lesser and greater burdock apart is based on size; the greater burdock is almost twice the size at maturity, and can have a taproot up to three feet long. For a plant that's only about three times bigger than that (but many in Canada don't reach that size), that's an enormous root! For all three species there are separate male and female flowers within the flower head. You can tell the difference by looking for the stigmas (the female bits of the flowers); they are pointed out with the bright pink arrow in the picture third from the bottom. Usually the stigmas only develop after the stamens of the male flowers have released their pollen; this way the plant can make sure the stigmas will catch pollen, but it won't be its own pollen; this is one of the mechanisms most often used to ensure cross-pollination between individual plants, rather than the pollen of an inflorescence landing on the stigma from that same inflorescence.

The burdock plant is pretty awesome for two reasons. First, if you look closely at the last picture you'll see that the burrs open up at the top to release the seeds, which are like miniature dandelion seeds, fluffy bit and all. The actual burr is covered in hairs with a hook at the end, and the tip of the hook has a very sharp point. This makes the burr feel "sticky" when you put it on your skin or when you grab at one, even though there's actually no sticky substance on the hairs. If you own a dog and have ever walked it through a forest or a field, I'm sure you're well aware of the nightmare that is "de-burring" a dog. The type of hair that covers dogs is just made for burrs using those hooked hairs to latch on for seed dispersal. Eventually, the dog will roll around on the ground, breaking open the burr and releasing the seeds (or the seeds will just gradually fall out of the hole in the burr, being released as the dog walks). Burrs certainly didn't co-evolve with dogs, but more like woolly mammoths, bears, moose, and other animals characteristic of northern climates (dogs just happen to be what is most likely to come by now). In the 1940s, a very smart man by the name of George de Mestral was getting very annoyed at having to pick burrs off of his dog after taking him for walks. After a few years of this he decided to clip some out of the dog fur instead of pulling them off so he could look at how the burrs attach to the dog hair. He realized he could exploit this technology; by collecting his dog's hair that comes off in brushes and the hairs of the burr, he could glue one to one side of two things he wanted to join, and glue the other to the other side. Once they come in contact, they would be permanently joined until they were carefully separated. Obviously no one wants dog hair and burrdock burrs glued to their clothing, but making synthetic versions of both of these gave us one of the most important inventions in the 20th century: velcro. Parents will small children: Mr. de Mestral I'm sure says "you're welcome!"

The other awesome part about this plant is that the giant taproot forming at the base of the plant is actually edible. Back in the Middle Ages in Europe this plant was actually one of many staple food crops, and was eaten and cultivated across Europe. Since then it has largely been abandoned as a source of food, but every so often you find it popping up in local cuisine. In Japan, for example, greater burdock roots are still peeled and cooked in a traditional stir-fry dish called kinpira gobo ("kinpira" for carrot, "gobo" for burdock). I didn't realize what I was eating at the time, but I had this dish when I was in Japan. It's pretty good! Not all that much flavour, but certainly not undesirable. I would definitely have it again now that I know what I'm eating.

Greater burdock roots also have a long history of being used in Traditional Chinese Medicine to treat blood and kidney diseases. Depending on what part of the plant is consumed (not the roots), it can be a pretty powerful diuretic, so if you don't know what you're doing, don't cook it. Other medicinal uses have not been established to be effective or ineffective, but there is some anecdotal evidence to suggest that some uses may be beneficial. First, the Ojibwa people have used burdock roots in a tea-like preparation to treat cancer (no evidence this is effective) and the leaves in a maceration with oils to treat baldness (also no evidence this is effective, but it does clean hair nicely if rinsed well). The Chinese also crush the seeds and consume the powder to treat flu, nausea and colds, and there is some evidence that this might be effective. The seeds contain chemicals called arctigenin, arctiin and aglycone, which have been shown in mice to be effective as: anti-viral treatments (especially against influenza A), anti-inflammatory agents (especially in the small intestine, but also to some degree in swollen joints as a result of arthritis), and anti-cancer treatments (extracts from the seeds, and pulverized seeds themselves, have been shown to kill tumour cells growing on artificial nutrient medium in petri dishes; this has never been tested in a living body of any type of animal). You never know; in a few decades burdock extract might be one of our new "wonder drugs"!

I'm back at blogging, and thanks for sticking through my absence! I really appreciate all of your continued support in my endeavours to spread the word that plants are awesome. Happy New Year to those that celebrate at this time of year!

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!

BLOG RERUN: Happy Diwali!

(a version of this blog post was originally published on November 13, 2012)

Diwali is officially tomorrow, but I might not be in a position to post a new blog tomorrow. Instead of posting a Diwali celebration blog a day late, I figured it's better to post it a day early! Happy Diwali! :)

Species name: Tagetes sp. (probably T. patula)

Common name: marigold

Location: picture 1 is from Teaching College English (click HERE), picture 2 is from eHow (click HERE), and picture 3 is from the WikiJunior Flower Alphabet (click HERE)

Tomorrow is the first day of a five-day celebration by Hindus, Sikhs, and Jains in India and around the world. It is known as the "festival of lights" or Diwali (or Deepavali, depending on what part of India you're from). I tried following how the exact date of Diwali is determined for any given year, but got lost after the mention of lunar days. For us non-Indians, it's sometime between mid-October and mid-November. This year it happens to be on November 3rd. So how does this relate to a blog about plants, when it's a celebration of lights? Well, read on...

With over a billion people of the world celebrating Diwali, and with it being the single most important holiday to Indians around the world, there is an enormous demand for decorations. Just like North Americans decorate for Christmas or Hanukkah (or whatever else you celebrate), Indians decorate for Diwali. And like any true Indian celebration, A LOT of flowers are involved. In fact, there are so many flowers involved in any Diwali household celebration that the demand for flowers in India skyrockets; a flower arrangement selling for 30-50 rupees on any non-Diwali day would sell for between 700-900 rupees tomorrow. I encourage you to name any other commodity in the world whose value increases that much over such a short time, just to fall right back down to what it was all within a week. There are people in India who make their entire year's salary in one week. It's an incredible phenomenon! So how does this relate to marigolds? Well, quite unusually, it turns out.

Normally, the celebration of Diwali involves decorating the ground in a specific pattern with rose petals. Because of the unfavourable weather earlier this year, roses are in short supply compared to what they usually are, and on a day like Diwali when there's a surge in demand, flower suppliers just can't keep up. They knew well in advance that there would be no way they could meet demands, and so substitutes needed to be made. Marigolds were always popular flowers around Diwali because of their colours, but this year they became extra valuable. The value of marigolds increased almost one hundred-fold for this year's celebration alone! Could there be a day that climate change causes a huge shift in how festivals like Diwali are celebrated? Perhaps. The flower supply market in Kenya, one of the leading producers of carnations, roses, gerbera daisies and baby's breath worldwide, has already started to suffer as a result of increased incidence of drought. While the temperature is not expected to change much (only 2-3 degrees Celcius by the year 2100; compare that to a projected 7-8 degree change for the Arctic), the incidence of severe weather patterns is expected to increase. Drought will be more widespread and worse than it is now, and when there is drought relief it is expected to be in the form of violent storms. Not exactly weather conducive for flower growing, in a greenhouse or not.

Marigolds themselves are some of the most highly praised garden plants worldwide. They are native to North and South America depending on species, but were spread worldwide for ornamental plant use by early world explorers. Marigold petals are added to a wide variety of food items for the golden colour they give off, especially when fed to chickens. It brightens the colour of the egg yolk and makes the egg appear (to humans; chickens don't care about the colour of their yolks) to be more nutritious even though the nutrition hasn't been changed at all. Marigold petals are also popular in herbal teas to balance out the bright pink colour of so many other herbal tea ingredients (like rosehips or hibiscus petals). The roots of marigold plants are full of antifungal and antibacterial chemicals called thiophenes, which are starting to be investigated as chemicals of possible medicinal value. The roots have been used for centuries by Native South Americans as treatment for fungal infections of their agricultural crops with moderate success. Unfortunately, North Americans and Europeans found out this antimicrobial effect the hard way; when planted near legumes, which rely very heavily on microbial activity in the soil, the yield of the crop decreases dramatically. The scent of marigold flowers is so pungent that it repels a wide variety of crop predators, and so can be useful when planted beside non-legume crops like tomatoes, potatoes, eggplant and peppers. The flowers of the marigold plant also attract pollinators, some of which will also eat insect parasites of crop plants like aphids. A great story of insect-plant mutualisms!

Happy Diwali to all of my blog readers in India, and Indians living around the world! Diwali ki Subhkamnayein! That's the best I can do...my keyboard doesn't speak Hindi :)

BLOG RERUN: The best boat ever made in nature

(a version of this blog post first appeared on October 31, 2012)

Species name: Cucurbita maxima

Common name: giant pumpkin

Location: photo 1 from Veggie Gardening Tips (click HERE), photo 2 from McShanes Nurseries (click HERE), and photos 3 to 6 from The Daily Mail (click HERE)

The giant pumpkin is actually a completely different species of squash than the regular pumpkin. When young (or more "natural" plants that have not been bred specifically for their oversized fruit), they are a completely different colour than regular pumpkins (almost red) and a very different shape. They are often sold in the grocery store as an edible squash variety, and called many names depending on their general appearance: banana squash, buttercup squash, Jarrahdale pumpkin, Kabocha squash, Lakota squash, Arikara squash, and the Hubbard squash. The giant pumpkin species originated about 4,000 years ago in southern North America (southern Texas and northern Mexico, but also perhaps as far south as Nicaragua) but was transported quite early in human exploration to Europe where species like it were already familiar to them. Cucurbita as a genus also has a second area of domestication around Burma, and since that was one of the stops on the great spice route, it was one of the groups of species that had been used by Europeans for centuries.

Growing giant pumpkins is a bit of an art form. To get a giant pumpkin to turn giant, first you need the correct variety. If you've ever consumed a Hubbard squash, you know how "regular sized" giant pumpkins can be. Once you have the giant fruit producing variety, the plant still won't produce a big enough fruit to enter into any giant pumpkin contests. To ensure that, you have to get crafty: you have to convince the plant that any sugars produced on a branch of the vine can ONLY be stored in the fruit because they have no where else to go. Normally plants can shuttle sugars produced in the leaves to any storage organ in the entire plant using their network of phloem, or sugar-conducting cells. Some plants make tubers underground (potatoes), and some make starchy or sugary fruit above-ground. In order to ensure that your one favourite pumpkin grows to an enormous size, you have to take a razor blade, and veeeeeery carefully cut the phloem off of the stem in a ring. This normally would be absolutely debilitating to a plant, and is called "girdling." A girdled plant cannot recover, and will eventually die. But what it does in the meantime is prevent the plant from conducting the sugars produced in that one branch to any other part of the plant. Instead, the plant just stores all of it in that one branch, in your soon-to-be-gigantic pumpkin. Some people also swear by watering with a sugary solution, but that won't do anything other than encourage microbial growth around the roots. This might be beneficial for a while, but sooner rather than later a detrimental fungus or bacterium will take over and rot the roots. Not a good idea. Ensure that the pumpkin gets enough water (because if you girdled the branch carefully, the xylem or water-conducting cells will remain intact), and sit back and watch your pumpkin grow!
Believe it or not, the seeds of the giant pumpkin are reported to have medicinal qualities. Fry the seeds in oil then grind into a powder, mix with sugar, then suspend that in castor oil. Drink it, and if you've got intestinal worms they will be no more. I think by the time you've resorted to drinking castor oil you're in pretty bad shape and would resort to any treatment, but to me this sounds like a disaster waiting to happen. There have been no scientific studies to suggest that this home remedy is remotely successful in the treatment of any human disease. Use at your own risk!

Since today is Halloween, I couldn't possibly pass up one of the most awesome uses of giant pumpkins that have nothing to do with carving them into jack-o-lanterns. Giant pumpkin regattas. Yes, you read that right. There are locations that actually grow giant pumpkins to turn into really awkward kayaks, then have races in them while the "pilots" are dressed in ridiculous costumes. There seem to be points awarded for creativity in decorating your "boat," too, since some of them seem to have some rather unusual additions that wouldn't contribute to the aerodynamics of their vessel. Don't believe me? That's why I have pictures.

 Pumpkins as helmets?! Not recommended.

Happy Halloween!

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!

BLOG RERUN: The Fruit of Thanksgiving

(this blog post was originally published on October 9, 2012)

Species name: Cucurbita pepo

Common name: pumpkin

Location: pictures 1 and 3 from Dave's Garden (dave), picture 2 from Dave's Garden (kennedyh), picture 4 from Dave's Garden (tman)

Since today is Thanksgiving Day in Canada, I figured I should post a blog about a plant that is essentially analogous to Thanksgiving in both Canada and the United States (yes, I know your Thanksgiving Day is in November...you weirdos!). That plant, of course, would be the pumpkin. What's Thanksgiving (or Christmas, for that matter) without pumpkin pie?!

Pumpkins are actually a specific variety of the species Curcurbita pepo, one that has been artificially selected for an over-sized fruit and the orange colour (or white, depending on the cultivar). The species Curcurbita pepo is actually one of the most variable and one of the most popular fruit/vegetable species that we currently have in cultivation. We get zucchini, acorn squash, delicata squash, dodi marrow, gern squash, heart of gold squash, pattypan squash, pumpkins, spaghetti squash, sweet dumpling squash, crookneck squash, and summer squash all from that one species alone! It's amazing what human selection for various traits can do to a species. This species is native to North America, but likely native to a region in the north of what is now Mexico, or the southern parts of Texas, New Mexico and Nevada.

Pumpkins are a great example of integrative agriculture, and how agriculture has changed over the centuries. Traditional plantings of pumpkins (or any squash) were not monocultures like you would see today (entire fields of nothing but pumpkins). Native North American people used to grow squash in association with corn and beans, and those three crops are what we now refer to as "the Three Sisters." Corn depletes the soil very quickly of nitrogen because it requires so much to grow, but beans create biologically-available nitrogen through the nitrogen-fixing bacteria in their root nodules. Beans are vines, and require props to grow so they wind themselves up the corn stalks to use them for support. Squash plants are very far spreading plants that cover the ground surface and don't require many nutrients (surprisingly enough), and due to their large leaf size they out-compete weeds for light resources. The three crops grown together create their very own bio-feedback ecosystem, and ideal harvests come from all three of these crops being grown together. Now with fertilizers and pesticides we no longer require the synergistic action of all three crops in one field, but you can see how this concept will become useful once we decide that dumping chemicals on our food is not the ideal way to grow plants. If you'd like to read more about the Three Sisters, you can do so HERE.

Happy Columbus Day to my American readers, Happy Dia de la Raza to my readers in Latin America, Happy Discovery Day in the Bahamas, Happy Dia de la Hispanidad to my readers in Spain, Happy Dia del Respeto a la Diversidad Cultural to my readers in Argentina, and Happy Dia de las Americas to my one lone reader in Uruguay!

Happy Thanksgiving, Canada!