Tuesday, September 24, 2013

BLOG RERUN: Is Weigela the new catnip?

(this post was originally published May 19, 2012)

Species name: Weigela florida 'Alexandra'

Common name: Old Fashioned Weigela, Wine and Roses Weigela

Location: My back yard, London, Ontario

This plant is native to Japan, and while not incredibly common it's not uncommon in its native habitat. During the winter this shrub is rather boring and...shrubby. The flowers usually appear first in April/May, with the leaves appearing relatively quickly after; green in the middle and maroon around the edges. The more the plant is pruned, the more it flowers the next year so the suggestion by gardening experts is to prune branches with flowers immediately after flowering ceases (so you know which branches had the flowers!).

No one has been able to explain to me why my cat is so very clearly attracted to these plants like a fish to water. I would even argue that if we had catnip planted in the back yard she would ignore it in favour of shoving her face into these flowers. She gets defiant when you try to pull her away from them, too, so there's obviously something pretty potent in the flowers that she smells that I don't. The flowers aren't overly scented, at least not by human standards. These shrubs are cultivated for their showy flowers and ornamental leaves, not flower smell.

Other than the obvious ornamental value this plant has, it has no other economic or medicinal value. To my knowledge, this plant isn't used in Traditional Chinese Medicine (many of the species in the genus Weigela are native to China) or by the ancient Japanese people as medicine or food.


So why choose to do a rerun of this blog post? Well, last Tuesday I said my last goodbyes to my kitty as I left the house in the morning. She had been sick only for less than a week, but she was too sick for it to be fair to attempt to keep her alive. My family and I will miss her every day; she really was the "little sister" of the family.

We'll miss you, Storm

"We go outside now?"

Monday, September 23, 2013

Welcome to fall!

Well, it's that time of year again: the 3-month bitter countdown to Winter. And so you know what that means: a blog colour refresh! I think last year at the beginning of the fall I changed the colours to be a brown background with orange highlights because those are very fall-like colours. This year, I decided to do the reverse!

The shade of orange that I chose immediately screams "pumpkin". The only part of fall that I actually look forward to is Halloween, and what a better reminder that Halloween is coming than a pumpkin-orange blog?! Then, after Halloween is over I get to savour that it has come and gone (hopefully with another costume contest win) and hopefully that will carry me through to spring. As anyone that knows me can attest, I HATE WINTER. I don't like snow, I don't like cold, I don't like ice, I don't like rain that turns to ice, I don't like never seeing the sun, and when the sun does come out it burns my retinas to a crisp, I don't like salt stains on the back of my pants, and I don't like my snot freezing in my nose. I. Hate. Winter. I definitely belong in a more tropical climate :) But it's not just the snow and cold and everything else that's gross about winter that I don't like; I also don't like seeing living things that actually look like they're living (notable exception here being evergreen trees and bushes). Instead you see a whole bunch of trees that have turned into sticks, with no pretty leaves or flowers in sight. Oh, how I long for spring again already... :)

But until spring rolls around again, you'll find me wrapped in a blanket with scarf, two pairs of mittens, three pairs of socks, sweatpants, a hoodie on top of a wool shirt, and a cup of warm tea staring at a beachy screen saver on my computer. Here's to Halloween coming! Are you dressing up this year?

Sunday, September 22, 2013

You put your left flower in, you take your left flower out...

Species name: Physostegia virginiana

Common name: obedient plant

Location: Western University campus

I didn't realize until after I had taken and water-marked these photos that I had already blogged about this plant once. If you'd like to go back and read the first version, you can do so HERE. If you'd like to read a "better than the last" version, keep reading! :)

The obedient plant is one cool plant. Endless hours of entertainment if you're lost in a prairie (more on that later). The native range of this tiny plant is quite impressive, ranging from the northernmost edge of the temperate forest in Canada all the way south to parts of the (very small bit that's remaining) tropical forests of Mexico. If grown in Canada it illustrates the reason why I should have made the species status diagrams with a "common, native, invasive species" combination because it spreads very quickly and can dominate a landscape in just a few years. Where there is snow during the winter the plant will die off, but because of the extensive underground network of rhizomes it will pop back up in the spring and produce more of the beautiful flowers. If you're thinking of planting this species in your garden, then go ahead and do so if you live in my area. It's a native species, and it's never a bad idea to plant a native species! You might want to reconsider, however, if you have an intense aversion to weeding (it will spread, trust me) or if your yard backs onto an Environmentally Significant Area. For those locations, even the slightest change in dominant species (such as providing a source for a seed bank of a weedy, although native, species) could spell disaster for the area. Always make sure you keep in mind what is around you before making major changes to the landscaping in your yard.

This species is one of the best examples of a member of the mint family, or the Lamiaceae. The stems of this family are almost always square, while nearly all other plant stems (the notable exception are the sedges) are round in cross-section. You can see the ridges of the square stems of this plant clearly in the third picture, above. The leaves are also characteristic of the mint family: they are simple leaves with teeth (some members of the mint family have leaves with smooth edges) that emerge from the stem directly across from each other. The next node up (or down) on the stem will also have opposite leaves but they will be at right angles to the previous level of leaves. You can also see what I mean by this in the third photo. The flowers are also very characteristic of the mint family, although different varieties of this plant have been modified in different ways (sometimes quite drastically) to be different than the so-called "wild type." A wild type plant is a plant that would be found growing in the wild without having experienced any intervention by horticulturalists (or, in the case of edible plants, farmers). The group of plants above are pretty characteristic of the wild type of this species: purple-pink flowers, the flower petals are joined at the bottom and form a structure that looks like two lips at the edge of the flower, darker purple or purple-pink splotches on the bottom lip, and the sexual parts (most noticeable being the stigmas) being attached to the top lip of the flower. This "two lip" morphology isn't done just by chance by the plant; it's actually a flower shape that has co-eveolved with the choice pollinator of this species: bees. Something that you may or may not be aware about bees is that they can't see colours like we see colours. Everything green looks a very dark blue to them, so picking out flowers from a sea of blue-black is difficult, especially when you can't see them. Bess are special, though, because they can see a wavelength of light that we can't see: ultraviolet light. This means that anything that's purple, or even purple-pink, will glow when a bee looks at it. The flowers themselves aren't quite purple, so merely act as lightly glowing beacons in the sea of blue-black plant material. This is enough to entice the bees over, but the dark purple patches on the lower lips of the flower is what really brings the bees over. The bees see the structure of the flower, and use the lower lip of the flower like a landing pad (those darker splotches would be like the landing lights that pilots use to land planes on runways at night). The bee would wiggle around, trying to get its head as deep into the flower tube as possible to access all of the yummy nectar. This would cause the bee's back to rub up against the stigmas of the flower (located on the top lip, which you can see in the fourth and fifth pictures above), which would dust pollen all over the bee's back. Once the nectar is gone, the bee would fly to the next flower, do the same thing, and transfer all of the pollen from its back onto the stigmas of the next flower, ensuring successful cross-pollination. Sneaky little flower! But also quite a smart little flower.

So why is this plant called the "obedient" plant? Well...it stays where you put it. Huh? The flowers actually have the ability to swivel around the flower stalk, and when the flowers swivel into a new position they stay that way. Check it out below:

In the top photo all of the flowers are pointing towards the ground, which is actually pretty common in this species once the flower heads flop over (often they grow too quickly for their own stems to support them if conditions are ideal). In the bottom photo I took two of the flowers by the base and swivelled them around to point straight up. They'll stay that way for up to a minute, then flop back to their original position. If you give the flowers a break, you can move them back and forth multiple times before the plant will just give up on those flowers and dissolve them off the flower stalk. Only the best are allowed to set seed!

Tuesday, September 17, 2013

Snowdrops sometimes turn into trees?

Species name: Halesia carolina (=? Halesia parviflora)

Common name: snowdrop tree, little silverbells

Location: Western University campus

To say that this plant has "a bit" of confusion surrounding the proper Latin name would be an understatement. There isn't just a bit of confusion, there's a whole lot of confusion. Linnaeus (the grandfather of modern taxonomy) was the one that first described this species, and even he admitted later that based on his "vague" description of the species he might not recognize it if face-to-face with it again. I guess that doesn't say much; some of the first biologists interested in assigning proper names to every living thing on earth often gave two, three, sometimes even four separate names to the same organism after forgetting they had already described it and with no Google Images to make the task easier, I don't blame them!

When the original description of a species is somewhat vague and someone else comes along later describing that species and assigning a new name, sometimes this new name becomes the official name. This happened for a while with this species, when Andre Michaux came along and not only provided a much more eloquent description of the species which contained more information, but also deposited a "voucher specimen" (or a portion of dried plant material kept in a dried and pressed plant library called a herbarium) that was much more informative than Linnaeus' specimen. In order for a specimen to be deemed "valuable" or "informative" to a herbarium and to future researchers, you need to be able to see a few key characteristics: either intact flowers or fruit but preferably both, both the front and the back of the leaves, an intact branch or portion of the branch showing the leaf arrangement on the branch, and any other important characteristics of the plant that could be used to distinguish species. If you just press a leaf or two and call it a new species, all green glossy leaves start to look the same after a while! The fact that Michaux's specimen contained both the fruit (of the previous year, which don't dislodge from the branch until the end of the flowering period the next spring) and the flowers as well as some leaves means it was much more valuable than half a fruit and four leaves. BUT. Life as a taxonomist isn't always that easy, especially if you're trying to "one-up" Linnaeus. Most taxonomists today concede that Linnaeus' description and specimen are "good enough" and so his name takes precedence (also because it is older). Regardless of the proper Latin name for this species, the status of the species and the native range doesn't change. The native range has now become highly fragmented due to the urban expansion of large cities; the snowdrop tree used to occupy a large range from Mississippi all the way southeast to Florida and northeast to North Carolina in the United States, but now only occupies a few small pockets in this area where intact forests remain. It is now widely planted around the world as a small ornamental tree, but this doesn't help the regeneration of the natural population. Given more deforestation (due to continued urban expansion or natural disasters like Hurricane Katrina), this tree species will almost certainly be at risk of extinction.

So what's so special about this tree? Well...it's pretty. And that's about all I've got. It's not a particularly outstanding tree for ornamental value, although it does have pretty white flowers (that don't usually have a very strong scent) in the early spring before the leaves emerge, then the unusual four-sided fruits that contain the seeds in the late summer through to the next spring. It's not a particularly good food source for any native Canadian animals since they don't recognize the fruits as being edible (that is, if they're edible at all; a single website states the fruits are edible and taste like cucumbers when still green but I don't recommend you experiment). The tree is incredibly slow-growing and rarely is taller than 10 meters in height. The tree often starts branching very close to the ground, giving it a bushy appearance, meaning the wood is also less than desirable for lumber purposes. The wood can often take on a very "knotty" appearance when grown in the presence of cicadas; they tap into the tree for the sap during the late summer (they use the tree's sap an energy source to make that buzzing sound). The tree goes a bit crazy trying to repair the "tap wounds" from the cicadas, and you end up with giant bulbs of woody tissue protruding off the main trunk and large main branches. Here in Canada the same thing happens, but often as a result of damage by other insects (which is strange, because we also have cicadas. Maybe they don't know they should be drinking snowdrop tree sap in Canada?). These protrusions make the tree look especially creepy at night because of the strange shadows the limbs cast.

Apparently this tree not only has an incredibly showy display in the spring with the flowers (which I'm ashamed to say I've never noticed despite this tree being right outside the building I work in), it also has a spectacular fall colour display. The leaves turn almost a neon yellow, which makes it stand out from all other yellow-turning trees before losing its leaves to overwinter. If I manage to catch the tree before it goes from "green to dead" (as I suspect many trees will this year with our first frost that we had last night...), I'll post an update with the fall colour and (if I remember this long down the road) another update in the spring when the tree is full of flowers.

The common name of this tree, for once, is actually something I can get behind. If you're familiar with early-flowering wildflowers, you will probably know and love snowdrops, sometimes called silver bells. If you've ever looked at them closely, they look an awful lot like the flowers on this tree except smaller and a clear difference between the petals and the sepals (sepals stick straight outwards, and the petals point down towards the ground). If you've never seen this tree before but have seen snowdrops, it will look a bit like you've picked a bunch of snowdrops and crazy-glued them to the branches of the tree to give it some colour. "Snowdrop tree" is indeed exactly what it looks like!

Wednesday, September 11, 2013

BLOG RERUN: The World Trade Centre Memorial Tree

(this post was originally published September 11th, 2012)

Species name: Quercus bicolor

Common name: Swamp white oak

Location: Ontario

I figured that today's blog post should have a special meaning, so the plant of the day is the swamp white oak. It is a native species to southern Ontario, with a species range almost completely overlapping with the previous day's blog, the pin oak. Like the pin oak, the swamp white oak can tolerate being partially submerged during the spring run-off, but unlike the pin oak it can also tolerate being submerged (either temporarily or permanently) during the growing season. Also unlike the pin oak, it is mildly shade tolerant and so is a good competitor in swampy forests.

So what about this blog post has special meaning? Well, as I'm sure everyone is aware, today is the 11th anniversary of the World Trade Centre attacks. While I don't personally know anyone that was in the WTC at the time of the attacks, or even know someone that knows someone that was in the WTC, I do remember my OAC ("grade 13") physics teacher stopping the class and turning on the TV so we could watch the news coverage. I remember the feeling of sadness of all of us in the class, and also the feeling of fear. None of us had ever stopped to think that this kind of thing even happened, let alone anywhere close to us. I won't ever forget where I was on that terrible day in history, and I don't think anyone else will, either. Unfortunately, the devastation of that day still rages on both in mentally in memories and in very physical ways. There are currently hundreds of firefighters and other first responders that are now battling unusual forms of cancer and lung disease because of the fumes they were inhaling while trying to save other peoples' lives. I heard on the news this morning that the American Government has finally agreed to pay for their medical treatment for their various cancers (previously it was limited to lung disease), which is a wonderful piece of news to hear.

In 2003, there was a competition to design a memorial for the former WTC site. The winning design was submitted by Michael Arad and Peter Walker, and includes two reflecting pools, a meeting area in the middle, and a mind-boggling number of trees. The memorial site was finally opened to the public on September 12, 2011, the day after the 10th anniversary dedication ceremony.

So where does the swamp white oak fit into this? Every single tree planted at the memorial site is a hand-picked swamp white oak from NYC and surrounding area. The workers on the site each got to choose a tree and a location to plant it within the memorial site, which ensures and almost "individualization" of each tree. The trees are all different sizes, different stages of maturity, and have different genetic backgrounds which help contribute to a spectacular colour show in the fall (the leaves of the swamp white oak change to yellow, orange or even pink depending on climate, light levels, and genetic background). A very neat idea, to say the least.

May we never forget the lives that we lost that day. If you see a first responder today, whether in NYC or in any other city around the world, thank them for their work. They selflessly put their lives on the line every time they walk into an emergency situation, and for that they should be commended.

Sunday, September 8, 2013

The Cornelian cherry tree isn't a cherry tree

Species name: Cornus mas

Common name: Cornelian cherry

Location: Western University campus

I must admit, when I saw that this was part of the dogwood genus I was surprised...very surprised. But the more I examined the tree, the more it started to make sense. I'll explain more below. The Cornelian cherry is native to eastern Europe through parts of the Middle East (Iran, Armenia, Azerbaijan) and into parts of southwest Asia. Throughout many of these countries it is an important plant for traditional food and beverage production (more on that below), and at times even part of traditional medicine. There is no status official reported for this species, but since reports state that the products obtained from the plant are "better" from wild plants as opposed to cultivated plants, it is actively harvested in the wild. This probably contributes to a declining population, but a full evaluation on population size and reproductive ability would have to be done before any drastic conclusions could be made.

So why did it surprise me to find out this was in the dogwood genus (Cornus)? Well, I walk by this plant every day on my way into school and on my way home from school and I've always been convinced it was some kind of rose. Granted, I've never looked that closely. But it's a rose, darnit! Alas...it is not a rose. The leaves, for one, are absolutely characteristic of dogwood leaves. They are perfectly smooth on the top and bottom, as well as having "entire" margins (the margins of the leaves don't have teeth, unlike the fine, or sometimes large, teeth of members of the rose family) and very prominent main veins and secondary veins (and the tiny net-like branches of tertiary veins appearing to be completely absent at the base of the leaf). The leaves are also opposite on the stem, an important identification characteristic of the dogwood genus. The fruit also confused me; oval fruits with a pit inside them similar to a cherry pit but more almond-shaped is characteristic of the rose family, but can also happen in dogwoods (although much less common). The flowers, if I had of paid attention to them in the spring, is what would have also given them away. The tree produces bright yellow flowers (the flowers of the rose family are white, light pink or bright magenta) with only four petals instead of the rose family's five. The flowers are also produced VERY early in the spring (sometimes as early as February during mild winters, but most often the end of March), sometimes months before the first leaves start to appear. All-in-all definitely not a rose, and definitely a dogwood. The overall shape of the tree, although very difficult to discern from the first photo because of the buckthorns that are starting to re-grow (despite the massive clear-cut of buckthorn that occurred during the fall of the year before), is also characteristic of dogwoods and not roses. Without pruning, dogwoods often grow to a "triangle" shape, where the lower branches are very far-reaching and the branches above that become gradually shorter as the tree gets taller, so the canopy makes a cone-like shape. Rose family trees on the other hand are much rounder in shape, and all of the branches tend to reach upwards instead of outwards. Tree shape, if you can actually see the entire tree, is often a great characteristic to use to identify individual trees, but beware of pruning which can drastically alter the natural shape of the tree.

I eluded to some of the uses of this tree above, and I would be interested in trying some of the traditional beverages produced by this plant. After reading that the fruit was edible, I went back and tried one. Let me tell you: ripeness is everything for this plant. Oh, goodness. The fruits of this plant are somewhat unusual in that they only fully ripen after falling off the tree. I figured I could get close enough by finding a really red fruit on the tree and giving it a chew, but it was one of the most unpleasant experiences of my life. IT IS SO SOUR!!! I thought my cheeks were about to explode. Since I figured I had put my body through enough trauma I should just find a clean-ish fruit off the ground and give it a try. And you know what? Still sour. But not unpleasantly sour. Just not something you'd eat a bucket-full every day. Definitely not something I'd do again...I try to make a habit of not eating things off the ground. So, the berries are sort of edible but not very pleasant. What to do with them? Well, if you've ever walked under a Cornelian cherry tree about this time of year, you've noticed the smell: sickeningly sweet, and rotting fruit. Do you know what sickeningly sweet, rotting fruit is good for? Making alcohol. The starches in the fruit are already starting to break down by natural microbial action (which is why the fruit go from smelling like nothing to smelling like pure sugar in a matter of a few days), so if some brewer's yeast were to be added then you would get quite a potent alcohol produced. This idea has been exploited in almost every single country that this tree is native to; in Azerbaijan and Armenia the fruit are used to produce vodka, in Albania an alcoholic "moonshine" like beverage called raki is produced, and in Greece a liqueur is produced where the berries are fermented, then more are added back into the fermented liquid to impart flavour. Vodka doesn't usually have much flavour, but that's partly because of what you start with: corn, sorghum, wheat and potatoes don't have much flavour. Starting with a fruit that packs quite a punch I would think would give the vodka a truly unique flavour; I would definitely want to give it a taste-test compared to some "regular" vodka. I'm not so sure I'd be keen on raki, since I'm not a big fan of homemade hard liquor (I've tried chicha once, which is a South American version of moonshine made out of corn. The first few sips were OK, but very quickly became too much to handle for me flavour-wise, texture-wise, and the strength of the alcohol content). The Greek liqueur also sounds pretty tasty, so now I have a new thing to add to my list of "things to eat and drink in Greece" if I ever manage to make it there on vacation. Instead of fermenting the fruit, in Turkey and in Iran the fruits are pitted, dried and salted for a Craisin-like snack, which also sounds pretty good (it would be like a salty-sour raisin). In Turkey the fruits are also boiled with water and sugar to produce a thick syrup which is consumed with sparkling water as a beverage called a "Sharbat", and when poured over shaved ice you can see how we might get the English word: sherbert (or sorbet in France or sorbetto in Italy).

The fruit of the Cornelian cherry aren't just used as a food item or as a means of producing beverages; they're also used medicinally. The fruits themselves are exceedingly high in Vitamin C (only 3-4 berries would be enough to satisfy your daily requirement of Vitamin C intake) and so are often used as a means of warding off cold and flu in eastern Europe. Once the plant made it to China in the 1500s, the Chinese quickly started using the fruit of this plant in Traditional Chinese Medicine to restore kidney function, and to retain the body's essence. I'm not entirely sure what that involves, but if it involves the prevention of catching a cold (which involves sneezing a lot, an action often viewed as the "expulsion of the soul" which is why in English we say "bless you" afterwards) it's probably pretty effective. The wood has also been used as an important material in the construction of hunting tools, sporting equipment, machine parts, and the handles of woodworking tools. The wood is extremely dense, and actually sinks in water (which is incredibly unusual for wood). This makes it extremely durable, resistant to decay, and much stronger than other types of wood. The bark is also unusual; while it looks like "regular" bark, when it is boiled it gives off a bright red dye which was traditionally used to make the Fez hat. All that from a single plant!

Wednesday, September 4, 2013

One version of the Rose of Sharon

Species name: Hibiscus syriacus

Common name: rose of Sharon, rose mallow

Location: my back yard (London, Ontario)

I personally love this shrub, but it illustrates how the term "invasive" is only meaningful to a small geographic location, and is certainly not a broad-reaching term. Most horticultural experts would say that this plant has the potential to become invasive, but only in areas where growing conditions are ideal (usually significantly further south than where I am). Well, obviously growing conditions are ideal here; this shrub is now taller than I am (and pruned every year) and wasn't there when we first moved into the house in 2006 (the neighbours have one that's probably 20 feet tall now; it's gigantic!). Pretty impressive for a shrub that was once considered to be intolerant to frost, so much so that people in Britain were strongly suggested against planting it in their garden but rather overwintering the plant indoors in the warm cellar. When Linnaeus (the grandfather of plant taxonomy or the naming of plants) first discovered this plant in the 1700s he knew it was native to Asia, but was convinced that the native range extended from the area now known as China and Korea all the way to the west to Syria (where he named the plant after). Unfortunately, his native range was a bit off and we now know that it doesn't extend much further west than India. The plant has been naturalized in many areas of the world now, ranging as far north as England (and Canada, for that matter) and as far west as Spain and Portugal. The flowers are very short-lived, so enjoy them on the plant while they last; typically a single flower bloom will be dead by the evening of the next day, but thousands of flower buds are produced on the plant in a single growing season. There's never much time during the summer where the plant isn't in full bloom. It shouldn't be surprising that this plant is one of the favourite food plants of those ugly "June bugs" that invade at the beginning of the summer; the plant and the bug are both originally from the same area of the world.

This plant is a great example of why I hate referring to plants exclusively by their common names. The common name "Rose of Sharon" can be used to refer to many plants, and this mostly depends on what era you're living in. Today, that common name is usually applied to this plant, the rose mallow, but other times it is also used to refer to an evergreen shrub with tiny yellow flowers native to Europe and southeast Asia (that is completely unrelated, might I add). In biblical times, the term "Rose of Sharon" was used to refer to at least four different plants depending on your geographic location: it could be a crocus growing on the Plain of Sharon, a tulip-like plant with bright red flowers growing in abundance in the Hills of Sharon, the Sharon tulip (a species of the genus Tulipa that is no longer grown in abundance as an ornamental species; in fact it is now quite rare), or the plant that we now refer to as the Madonna lily. But, of course, interpretations of the Bible change, and now most biblical scholars have agreed that the name "rose of Sharon" is actually a mistranslation from Hebrew and should actually be "crocus of Sharon" if you're referring to the biblical plant, and is actually referring to the now critically endangered plant known as the sand daffodil or the Lily of St. Nicholas which is neither a daffodil, nor lily, nor is it a crocus. So! Can we all agree that common names are silly? :)

The "real" rose of Sharon, at least my version of the rose of Sharon, is a plant that is of great importance to the people of South Korea (perhaps North Korea, too, but finding out for sure is obviously problematic). The flower of this plant is the national flower of South Korea, and it is also believed that it is an important medicinal plant. Traditional Korean medicine uses the flowers and leaves of this plant brewed in a tea to ensure eternal life (whether this is actual eternal life or proverbial eternal life I'm not sure), and the leaves and flowers are also commonly eaten during special events or special ceremonies. I've tried chewing a bit on the leaves of this plant and find it...unpalatable at best. With Korean food being as spicy as it is, I find it hard to believe you could pick out the flavour of the leaves, but that might change with cooking (and they might be used in mild dishes, too. I'm not sure). I still haven't brought myself to try eating a flower; the thought of eating flowers still seems like a botanical injustice to me. Why would I want to eat something so pretty?!

Sunday, September 1, 2013

Green tea: won't cause you to lose weight or prevent cancer, but tastes good!

Species name: Camelia sinensis

Common name: tea plant, tea tree (see below for why you should never call this plant a tea tree), tea shrub

Location: teaching lab at Western

For the last "Plants as a Human Resource plant profile," I figured I would do one of my favourite plants in the world, and one that I exploit multiple times per day: the tea plant. The tea plant (often referred to by it's Latin genus, "Camelia") is native to China, as are all plants with the species epithet "sinensis" (it means "from China"). There are two major varieties of tea plants: one that was domesticated in India and the Middle East called Assam tea (C. sinensis var. assammica), and the other that was domesticated in China and known as Chinese tea (C. sinensis var. sinensis). There are two other recognized varieties but these are only used locally for tea, not shipped to international markets. If the tea you buy is just referred to as "tea," you can be almost guaranteed that it refers to Chinese tea, as Assam tea is almost always specified on the label. It does have a slightly different taste, and when the leaves are cured it brings out the difference in flavour. It would be appropriate to note here why I say above that the term "tea tree" should probably not be used to refer to this plant, despite the fact that it can reach "tree height." When you call something a tea tree, most people think of an essential oil that is referred to as tea tree oil, used in cosmetics and in fragrances (sometimes now used medicinally in herbal medicine, too). This is NOT the same species, and this extract is from the leaves of the tea tree plant, or Melaleuca alternifolia. Please don't drink tea tree oil...your digestive system will hate you for it.

One thing that catches many people off-guard is that ALL types of tea (black, white, green, yellow, oolong, and pu'erh) come from this plant. The way that the leaves are treated after picking is what determines what type of tea the leaves will become. There are also differences in when the leaves are picked, and how many are used in the making of different types of tea.

Black tea: leaves are picked and then allowed to fully oxidize. The leaves are fully oxidized when they turn black and start to roll inwards. The leaves may then be dried and packaged (being cut before or after drying, or left whole), or they may be flavoured before drying. Earl Grey tea has bergamot flavouring added before drying (bergamot oil is extracted from the skin of the bergamot orange), English breakfast tea is made up of plain black tea leaves, Irish breakfast is a blend of Chinese and Assam tea leaves, and Masala chai is a blend of black tea leaves and other spices (and often sugar).

Green tea: the newest leaves are picked, rolled, and immediately dried with minimal oxidization. This allows for a much milder taste, and a taste that blends well with other flavours for tea blends (like dried fruit pieces or other mild flavourings like flower petals). The quality of the leaves, the amount of time they are given to develop on the plant, and the environmental conditions the plant was subjected to during growth all play major roles in the flavour of the tea. Lower-quality teas have a much more bitter after-taste to them than higher-quality teas, and if you compare a good quality green tea to a poorer quality green tea in a taste test you'll be able to tell the difference right away. Because of the lack of oxidization of the leaves, this leaves all of the chemicals intact that many claim have health effects (more on that later).

Matcha tea: this is just a specific cultivar of tea plant where the leaves are dried without oxidization and then ground into a powder. This powder is whisked into warm water until a frothy-like consistency is reached, and then consumed. Many proponents of green tea having positive health effects say that matcha has a much larger effect on health because the leaves themselves are also consumed (unlike drinking traditional green tea).

White tea: this is a special type of green tea, where the leaves are allowed to wither on the plant before they are picked and dried. This prevents the oxidization process, but the leaves are "bleached" on the plant so they are nearly white in colour. This is emphasized by the fact that the leaves are very young and still have a dense covering of white hairs, which make the leaves look even lighter in colour. The term "white tea" does not refer to the colour of the beverage, just like "green tea" doesn't refer to a beverage that is green. If you get a cup of white tea that looks like water...you've just been served water. If you get a cup of green tea that is green (and it's not matcha, which is bright green in colour), you've been served a cup of bad quality green tea and green food colouring.

Yellow tea: this is a relatively uncommon type of tea, where the leaves are allowed essentially to rot slightly while being dried very slowly. This gives the leaves a yellow-ish appearance, and gives a very different flavour to the tea. I have yet to try yellow tea (or see it for sale in many places) myself. Sometimes the term "yellow tea" is used to refer to tea that is either green tea or white tea that is served in the Imperial court (just to make things more complicated).

Oolong tea: this type of tea is almost an intermediate between white tea and black tea. The leaves on the tea plant are allowed to wither during extreme sun exposure during the hottest months of the year, then picked and fermented (not fully fermented like black tea, but fermented enough to give a smoky and full-bodied flavour). The amount of fermentation depends on the quality of the leaves picked, and in some areas in China only one specific cultivar is used to make oolong teas. The withering of the leaves causes them to curl and twist, so watching oolong absorb water during steeping is often a sight to be seen. What looks like tiny little fragments of tea leaves actually unfurl into complete leaves. It's like magic!

Pu'erh tea: this is a type of tea produced exclusively in Yunnan Province in China, and it is made by fermenting and oxidizing the leaves of the tea plant after drying. This gives the leaves a very unique flavour which is difficult to describe, but also allows for customized fermentation and oxidation prior to shipping. The leaves are, more often than not, packaged in "cakes" to be sold and wrapped in decorative foil. This actually allows for the continuous oxidation and fermentation of the leaves during shipping and storage, which is referred to as "aging" the tea. Sometimes tea cakes are shipped immediately and may be aged by the purchaser or used right away (the flavour, and colour of the steeped tea, differs drastically depending on amount of time left to age). Other times tea cakes are allowed to age at the factory, then shipped. These are usually consumed immediately, and are very expensive to buy. The cakes are packaged with "tickets," that are always stamped with a four-digit number. The first two of these numbers represent the year in which the recipe for that specific type of pu'erh cake was developed, the third number refers to the grade of the leaves used (the smaller the better), and the last digit refers to the specific factory in which it was made. To use the leaves, they are often just chipped off the cake until the desired amount is separated, but sometimes the entire cake may be steamed to loosen all of the leaves (and then they would be stored in an airtight container after re-drying). Often a pu'erh knife is used to loosen shavings of leaves from the outer surface; you never take a "slice" of a pu'erh cake because the amount of fermentation and oxidation from the outside to the inside of the cake differs drastically. Sometimes pu'erh tea can taste "fishy" if it is fermented or oxidized too quickly, which is often a sign of poor quality. Choose your pu'erh wisely!

Onto the health effects of tea. For the most part, black tea might be a tasty beverage but it is almost entirely lacking in the polyphenols that tea is known for. If you want to drink tea to be healthy, put the Earl Grey and English breakfast back on the shelf and find yourself a good-quality green tea. There are four diseases or disorders that tea has been shown to have proven positive effects, as demonstrated in large-scale clinical trials. The first is in calming the symptoms of asthma. When green tea is consumed on a regular basis it can act as a bronchodilator, which would increase the air flow to the lungs. This does NOT mean that if you're having an asthma attack you crack out the green tea and make yourself a cup. "Green tea therapy" for asthma is used in conjunction with emergency inhalers and also the everyday inhalers; the idea is that asthma attacks will occur less often, be less severe, and everyday inhalers could be at lower doses and be used less frequently. The next three diseases all have to do with dilating the vascular system; regular consumption of green tea has been shown to help decrease the severity of angina, peripheral vascular disease, and coronary heart disease by increasing the diameter of the blood vessels, allowing for better blood circulation. This definitely won't cure any of the above diseases or prevent you from getting them, but if you are at high risk of developing any of them then it may help prolong the onset (or decrease the severity of the symptoms). That being said, the number one and number two risk factors for all three of those disease are no longer related to inheritance from your parents; they're now obesity and smoking. So do yourself a favour and quit smoking and get out and exercise!

There are a lot of other claims out there about the health benefits of drinking green tea, but so far none of them, I'll repeat that in big letters, NONE OF THEM, have been demonstrated to be true in large-scale clinical trials. People will tell you drinking green tea regularly will decrease your cholesterol and prevent the onset of cancer, neither of which have been demonstrated. Extracts from the tea leaves from the plant (the key here is from FRESH leaves. Are these chemicals still there in quantities that are useful to the body after drying and then steeping in boiling water? Unlikely) have been shown to have anti-cancer properties and the ability to reduce cholesterol but these effects have never been demonstrated in humans. There's also the strong suggestion that drinking green tea will contribute to weight loss, which I find incredibly hard to believe. Any kind of caffeine intake will "contribute" to weight loss if you don't take in more calories than you burn, because caffeine is a stimulant. Will drinking green tea specifically cause you to lose weight? No. Exercise and burning more calories than you consume causes you to lose weight. If you want to lose it, you need to put in the effort. Don't fool yourself into thinking you can drink some tea or take a pill made of green tea extracts and the pounds will melt off.

So are there any benefits to drinking green tea, other than the four mentioned above? Well, the jury's still out. There's evidence that the consumption of green tea SHOULD be beneficial, but nothing has been proven yet. That being said, there's absolutely no evidence that green tea is harmful to you, and if you're concerned about pesticide use there are now an over abundance of companies that produce organic green tea. Just don't go overboard; remember that tea does contain caffeine (although much less than coffee), and if you're drinking it to be healthy you can't be adding milk (or worse, cream!) or sugar. Learn to love the purity of the leaves :)