The North American planetree

Species name: Platanus x acerifolia

Common name: London planetree

Location: Western University campus

As promised, this blog is about our version ("our" referring to the North American meaning of the term) of the planetree. Ironically enough, it's called the London planetree not after London, Ontario, but after London, England. A half-British, half-American name for a European species. Just when you thought common names couldn't get any more perplexing... :)

The planetree is a hybrid, which makes its native range essentially a moot point. But for the purpose of a species status diagram, it's a non-native species since the hybrid is rumoured to have been first discovered in Spain in the 1700s, but was first officially described by a Scot in 1789 as a variety of the Oriental sycamore, or Platanus orientalis. It was elevated to the status of species in 1805 by Willdenow (Platanus acerifolia), but it is now widely believed to be a hybrid of the American sycamore and the Oriental sycamore (sometimes called the Chinese sycamore or even the Oriental plane). It looks like an exact intermediary of the two species: has leaves with lobes not nearly as shallow as the American sycamore but more shallow than the Chinese sycamore, fruits in pairs instead of singly like the American sycamore (the Chinese sycamore usually has 3-6 fruits in a group), and light green inner bark unlike the white bark of the American sycamore and the much darker green bark of the Chinese sycamore. I love it when hybrids are a 50/50 blend of the parent species! It makes life so easy.

So why would you want to plant a hybrid species, when the American sycamore is a native species and looks pretty darn similar? Well, for one, the planetree is much more tolerant of urban conditions like pollution and root compaction, as well as being much more drought-tolerant and so doesn't require the riparian habitat that the American sycamore does. It also doesn't get nearly as large, which is often beneficial in cities (you don't exactly want a 5 meter in circumference tree growing between a sidewalk and a road). It is also much, much less susceptible to a fungal disease called anthracnose, which is quite common in American sycamores. So far it sounds like a pretty good compromise! Unfortunately, all good things must come to an end. The planetree actually has a really nasty side to it in the spring: it is highly allergenic. The new growth of the tree produces tiny hairs on the surface of the leaves, the leaf buds, the branches, and the fruits. As the tree sheds these hairs while it matures, they blow off in the air and (usually) end up up your nose. Here, they attach to just about anything they can get ahold of, and trigger a severe immune response (this isn't just your typical pollen-allergy runny nose). Some people have even reported a skin response that looks like a second-degree burn as a result of coming into contact with many of these hairs (say, for example, grabbing onto a young branch in the spring) and the resulting rash is a hyper-immune response. This effect tends to decrease as the tree ages, but if you plant a young tree, be warned. Now that I know this, you won't catch me coming anywhere near one of these trees in the spring. I have really sensitive skin, and with my luck I'd be the one that ends up with giant pustules all over my hands and arms! The leaves are also difficult to deal with in urban settings as the leaves produced on mature branches are very thick and leathery. If left to rest where they fall, they can take years to start to decompose (unlike a few months like most leaves, which is why they make great compost starters and mulch). This means they are problematic to deal with in the fall clean-up to prepare streets for winter.

Planetrees are sometimes planted for lumber and logging purposes because of the very attractive wood (it's a light yellow wood with red flecks). In the lumber industry it's often referred to as Lacewood, and is used in wood trim or decorative panels in fine furniture.

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!).

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!

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?!

Can you help me identify my tree?

Species name: Rosaceae

Common name: you tell me!

Location: my backyard

Shockingly, I have managed to find a tree I can't identify. That might sound like a cocky statement, but that's certainly not how I intend it; if you have the right resources and identification keys you should be able to identify any tree growing in a planted area in a garden (any garden), but I am completely stumped! I've managed to narrow it down to the family based on the flowers: white flowers with five petals and numerous stamens. It should be reminiscent of strawberry flowers (since strawberries are also in the Rosaceae, or the rose family). That is where my abilities at identifying this tree end.

It doesn't matter what species I look at, native or non-native, none of them quite fit. The leaves are similar to serviceberry leaves, but the flowers are different (serviceberry flowers also have five petals, can be white but also slightly yellowish, but the petals are MUCH narrower than in these flowers). It looks similar to a Saskatoon-berry, but the leaves are much too pointy, not broadly rounded at the ends. The flowers look similar to crab apple flowers but the leaves don't have the prominent lobes of the wild crab apple or pacific crab apple, and don't have the correct leaf shape for the common apple or the siberian crab apple. Cherry leaves, also trees in the Rosaceae, are the widest at a point above the mid-line of the leaf (so if you were to cut a leaf in half cross-wise, the top half of the leaf would have the widest point, not the bottom half like would be the case with these leaves). It could be a pin cherry, but I've never seen the bright red berries that are characteristic of this species. Choke cherries are similar species, but the flowers are arranged in dense elongated clusters at the tips of the branches, which is not the case with the tree in my back yard. Canada plum is another possibility, but this species has characteristic thorn-tipped dwarf shoots which my tree doesn't have. This characteristic (or lack thereof) also eliminates all hawthorns, but they also have very different leaves with defined larger teeth, as well as the smaller serrate teeth (sometimes called "double dentate").

So what DOES this plant have? Well, aside from what you can see in the images (surprisingly enough, that leaf picture actually tells an interesting story, although I don't know if it means anything biologically). The leaves are always arranged in threes on the tips of short-shoots off of branches, even at the top of the tree. This tree is growing in a heavily-shaded area, and only the top of the tree would ever receive direct sunlight. Also interestingly, hardly any of the flowers develop into fruit, yet there are always tons of insects around the flowers scavenging for nectar and pollen while they are open (the flowers have no noticeable scent that I could discern). I went back to this tree (pictures originally taken May 26th of this year), and there's only one tiny fruit on one branch that I could see; it was about the size of a pea and completely green. I'll go back and update this blog if it grows and turns colour before it disappears in the hands of a bird or squirrel.

Here's your challenge for the day: help me identify it! Have you ever seen a tree like this before? Do you have one in your backyard? Do you work at a greenhouse and sell this tree? I'm almost positive it's a non-native species (only because of its lack of fruit production, implying it might have some sort of specialized pollinator that we don't have in Canada) but I might be off the mark. Someone tell me this is an incredibly rare species! :) Any and all help welcome.

A hippopotamus of a bulb

Species name: Hippeastrum sp.

Common name: "amaryllis"

Location: Ontario

Since I'm still not done going through all of my plant pictures from the Dominican, I figured I would profile a plant from my house! Every year, my grandma gives an amaryllis bulb to every family and there's a friendly competition to see who can get the first flower, the tallest flower stalk, the shortest flower stalk, a bulb that doesn't grow (this always seems to go to my uncle Steve, who couldn't get a weed to grow even if he tried), and the most number of flowers. There are no prizes other than the right to brag to everyone that you know that you're better and/or worse at growing a bulb than the rest of your family. Apparently this is fun...

The plant that has the common name of "amaryllis" actually isn't an Amaryllis at all. The common ornamental species of Hippeastrum (there are approximately 90 species in the genus) are native to tropical and subtropical regions in the Americas, from about Mexico and the Caribbean south to the northern half of Argentina. The appearance of the flowers of this genus can be wildly different, but they all have three things in common: the plants are called "bulbous perennials" (they flower every year from a bulb and live for many years), the flower stalk is the first green part to emerge from the bulb, and all of the flowers have 6 tepals (3 petals and 3 sepals which are indistinguishable from each other once the flower is mature). The true Amaryllis, however, is native to South Africa and is starting to become more and more common throughout the world as ornamental species. The two genera are morphologically similar, but they can be easily distinguished if two species are side-by-side. They were both thought to originally belong to the genus Lilium, which contains all of the "true" 6-tepaled lilies, but DNA sequencing has shown that this is definitely not the case (it was no longer believed to be the case, even before their genes were sequenced; all lilies are highly toxic and have very different growth morphologies than either the amarillii or "amarillii"). There are significantly more issues with the taxonomy of these two genera, but I'm not going to get into that; if you want to read about the issues, you can read the "taxonomy" section of the Wikipedia article of Hippeastrum HERE.

One of the aspects of the indoor amaryllis that makes it such an ideal houseplant is the ease of growing it: put the bulb into some soil (it can be significantly less soil than you think should be able to support how big the plant will actually get), put it in a window, and water it once a week. Seriously! That's it. Some bulbs take longer than others to flower the first time because of the amount of nutrients it managed to acquire the season before; if it doesn't flower right away, give it some time and perhaps put it into a sunnier, less drafty window. The roots will become well-established and will funnel nutrients to the bulb, allowing the flower stalk to start to emerge. It is green when it first starts growing, producing sugars for the rest of the plant to use as fuel for growth. Not long after the flower stalk emerges from the bulb the leaves will start to grow, and within a few weeks you should have something that's starting to look very much like a traditional amaryllis. The varieties and cultivars used for their ornamental value and packed in boxes in November and December are usually grown for their enormous flowers and very long flower stalk; this is typically not how the plants would look in nature (and the last image should give you a hint why if you're observant). The height of the flower stalk and the weight of the flowers is far too much for the plant to handle on its own, and you're going to need to resort to staking up your plant unless you want soil all over the floor! Once the flower stalk is done flowering, you might be lucky enough to get seeds produced, which you can plant in new pots and get new plants growing from seed. Be warned, however, that the offspring will likely look nothing like their parents; genetic recombination that occurs during fertilization means that genes will be shuffled and some that produce the ideal flower and plant morphology of the bulb you bought in the box will be lost.

Once the flower stalk dies, clip it off at the base and allow the leaves to continue to grow and produce sugars that are stored in the bulb (this is where it's important to ignore all information about how to properly grow an amaryllis that's on the box). The leaves will gradually yellow and start to decay; that would be a good time to pull them off the bulb (they should detach very easily at the bulb). Eventually, you'll be left with just a bulb in a pot. Water the bulb very sparingly (as in, not at all or once a month at most) until December rolls around again, and then water it whenever you remember, but no more than once every couple of weeks. Once it's ready, it will start to grow a new flower stalk. Water once a week, and voila! A new flower. Don't get discouraged if it doesn't flower again the second year; some varieties can only afford to flower every other year because of the number of resources it requires to produce the flowers.

(one of) The real jade plant(s)

Species name: Crassula ovata (formerly Crassula argentea)

Common name: jade plant

Location: UWO Greenhouse

This plant is a wonderful example of taxonomy and taxonomic rules. A few days ago I profiled the trumpet jade, which is a variety of the jade plant selected for its morphologically messed-up leaves (you can read all about it HERE). It is native to South Africa, and has (to my knowledge) never been evaluated for its species status. It is likely very secure (meaning there are many individuals left in the wild that readily reproduce), but since I've never been to South Africa I'm definitely not one to comment first-hand.

Historically, the jade plant was divided into two different species based on flowers; the pink-flowered plants were placed in Crassula ovata and the white-flowered plants belonged in Crassula argentea. There is also a correlation between colours of flowers and the general shape of the leaves; the leaves of the pink-flowered plants often have longer and more oval leaves, while the white-flowered plants have shorter, slightly rounder leaves. Unfortunately, this was just smoke and mirrors and a great example of how plants confuse botanists. The "rules" that were made up for how to tell C. ovata from C. argentea were 100% artificial, and it turns out they're both the same species. The colour of the flower is controlled by a single gene and there can be gene copies for white flowers or pink flowers. Depending on whether the plant has white genes or pink genes, the flowers can be more white, more pink, or somewhere in between. Leaf shape is probably more controlled by level of maturation and environmental conditions than anything else; leaves produced in very dry conditions and high amounts of sunlight will be smaller and more ovate than ones produced when lots of water is available and the temperature is cooler.

So once a species has two names, what do we do? In the naming of any kind of biological organism, there is a rule called the "Rule of Priority". Whatever name was validly published and applied to the organism first is the name that stays. There are some ways to make exceptions to this rule (especially in animals...zoologists are terrible with following rules of taxonomy!), but I won't get into that. If I don't get to bend the rules with my thesis when I'm naming species, no one else should :)

This jade plant has been masterfully cared for. How do I know this? Look at all the flowers! I've seen the odd flower or inflorescence group on a jade plant before, but nothing like this. One thing that you often have to be careful of when it comes to flowering plants (and some non-flowering plants that are gymnosperms) is that when they "moult" because their health is suffering, it's often mistaken for a sign of great health and prosperity. Some trees are known to do this: the tree somehow knows that it is infected with some kind of disease (insect, fungal, bacterial or viral), produces significantly more seeds than it would under normal conditions, then dies pretty quickly after the big seed flush. Oak trees also do this on an incredibly predictable cycle, which is off-set with population booms of squirrels. When the squirrel population is high, the oak trees need to produce an over-abundance of acorns just to keep up. They moult and over-produce acorns in an effort to overwhelm the squirrels and hopefully reproduce instead of being completely eaten. The results of this effort can sound like it's literally raining acorns. This effort seems to be incredibly successful, since most species of oak aren't at risk of becoming endangered due to squirrel predation any time soon. The moulting of oak trees depends on the species; red oaks are on a 4-5 year cycle and white oaks a 5-7 year cycle. Is this jade plant at risk of keeling over after this flush of flowers? I'm guessing not, but I'm really not sure. If it's mysteriously absent from the greenhouse in 8-12 months, then I think I know why! If it's still there, then its just a well-loved jade plant.

What is the proper name for this plant?!

Species name: Kleinia mandraliscae (or perhaps Senecio mandraliscae, or perhaps neither of these...)

Common name: blue chalk sticks

Location: UWO Greenhouse

This plant was rather interesting to identify; it took me a long time to accept that I had found the correct plant because of the plants it was most closely related to. Blue chalk sticks (a pretty awesome common name, even if the "sticks" are leaves and they can't be used like chalk even if you dehydrate them) are native to South Africa and the surrounding area, in dry, hot locations. They are succulents, meaning they store water in their leaves to use during times of drought. And that's basically all I could find out about this plant!

When it comes to plant identification, it's amazing how little can be found about certain plants. This one, for example, doesn't actually seem to exist. It was previous named in the genus Senecio, and I'm not entirely sure how it got there. Senecio, or the ragwort or groundsel group, is closely related to the common dandelion (which you can read all about HERE). If you picture what this plant and what a dandelion look like, they look absolutely nothing alike, not even if you use your imagination. I've never seen the flowers on this plant, but I can't imagine them looking like dandelions, either. Somewhere down the line this species was moved into the genus Kleinia, which doesn't seem to have a common name. The affinities (the closest relatives) of these species are still up for debate since none of them have had their DNA sequenced. The icing on the cake with the blue chalk sticks is that according to Wikipedia (a remarkably accurate resource when it comes to current taxonomy), this species doesn't exist in any genus. One page says it's a Kleinia, but links to a page with photos that calls it a Senecio, but neither of the pages which list species names of either of these genera have it listed under current species. So where does this species belong? What is its current name? What are its closest relatives? Your guess as to the answer of these questions is as good as mine.

My thoughts: this plant is actually just a blue variety of Senecio barbertonicus. Based on images, these two species look strikingly alike, except for the colour of their leaves. I'll have to keep going back to the greenhouse to see if I can catch this plant flowering to see if the flowers are the same. There are some exceptionally odd species of both genera (Senecio and Kleinia) that are only known from cultivation, which should make you wonder if they're true species at all. This is a perfect demonstration of why we need to sequence more plant species so we have an idea of the diversity on Earth. Right now we really are flying blind!

The Brazilian jasmine native to Brazil, not the Chilean jasmine native to Argentina

Species name: Mandevilla sanderi

Common name: Brazilian jasmine

Location: UWO Greenhouse

Brazilian jasmine is native to (you guessed it) Brazil, and until recently was considered part of a separate genus from the rest of the Mandevilla species in the genus Dipladenia. Most of the species currently classified in Mandevilla are native to Ecuador; this is one of the only species that's not. It's also one of the only species in the genus that's not critically endangered. It is still relatively common in the Brazilian rain forest, although the forest itself is decreasing in area by about 5-10% per year, so it will also soon be at risk. The common name of this plant is sometimes Chilean jasmine, but that common name actually refers to another plant, native to Argentina (yet another reason why common names of plants bother me...)

One of the characteristics of this plant that make it so attractive to gardeners (especially those with an indoor green thumb) are the strongly scented flowers. When in the appropriate location (in full to partial sun), these vines can reach heights up to 10 meters tall if given a support system in one growing season. If you want to encourage bushier growth, pruning the plant back almost to ground level every fall to encourage new growth in the spring would be best. The flowers can be tricked into being produced repeatedly during the growing season if the old flowers are pinched off (also called dead-heading). When grown in a container (either indoors or outdoors), it will rarely reach a height taller than a couple of meters.

There are no reports of this plant being toxic, but also none of it being edible. It is sometimes used in the perfume industry because of its scent, but doesn't have any other value aside from an ornamental plant. In the garden it will attract hummingbirds and butterflies because of the shape and colour of the flowers (and also a few bees...!).

The Japanese can't make their own taxol from their yew

Species name: Taxus cuspidata

Common name: Japanese yew

Location: Ontario

You might be wondering why I'm featuring the same plant twice in the same week, but you would have made one vital assumption that is incorrect: just because two species look the same doesn't mean they are the same. The Japanese yew, featured here (native to Japan, as you might have guessed), is a very close relative to the Canada yew, featured in my blog post on Monday (read all about it HERE). In fact, by assuming that the photos above represented the same species as that of the Canada yew, you would be making the same error that many botanists have made in the past; it was only recently demonstrated that there are distinct species within the genus Taxus. The genus was originally thought to be monotypic, and instead having distinct geographic races or subspecies that are on their way to becoming their own species, but have not yet become distinct enough to warrant the title. The Sumatran and the Mexican yews are the most different from the type species, the European yew. These were the first to obtain their own species designation, with every other species following suit and being confirmed through DNA sequencing.

So if these species are so morphologically similar, how do you tell them apart? Well, the needles and their arrangement on the branches is the first clue. The needles of the Canada yew are arranged around the branches when young, but the development of the bark on the branches almost flattens out the arrangement of the needles as it matures. If you look at the branches that are brown in colour instead of green (showing that bark has been formed), the needles are in two rows on each side, but are flattened on the branch. It has almost become two-dimensional. The difference in the maturation of the Japanese yew branches is that the needles remain spirally-arranged on the branch; they never flatten out unless something has been grazing the branches. With age, the needles also turn upwards, so all of the oldest needles on the inside of the shrub or small tree are pointing upwards, even though their point of attachment on the branch is all the way around it.

The second hint that these are different species is their sheer size difference. The Canada yew barely reaches a height of 2 meters off the ground and completely lacks a central stem. While the Japanese yew pictured above doesn't really look like it has a central stem, it is clearly more "tree-like", and the branches have the ability to support their own weight as opposed to drooping onto the ground like the Canada yew branches do. The Japanese yew can also grow to a maximum height of 18 meters.

The last major differences are not visible to the eye, but rather "visible" to a machine called a gas chromatography mass spectrophotometer, or GCMS. These machines are also sometimes called the "mass spec," and if you watch CSI at all you will have heard of them! They really do exist, and they are used in much the same way as suggested on TV (but not nearly as quickly, and the results are a bit harder to interpret than what the shows make them out to be!). You dissolve a bit of an unknown substance into a solvent (usually some sort of alcohol, although other organic solutions are sometimes used like chloroform), and inject a very small quantity into the machine. The machine separates the individual components of the liquid mixture by molecular size, and displays a graph of molecular weight versus abundance. The shape of the peak tells you what types of chemical bonds are present, and the location along the size axis tell you how big the molecules are. The height of the peaks tell you how much of any given substance are present. So what does this have to do with the Japanese yew? Well, it's a rather unfortunate tale for the Japanese; if they want to make their own paclitaxel, they're going to have to start planting Canada yew. The Japanese yew doesn't contain the right combination of taxanes to have the desired medical effects. In fact, the Japanese yew is exponentially more toxic than the Canada yew; it has the distinction of being the "Japanese horse killer." Just five needles are enough to kill a small dog. If you choose to plant this ornamental tree in your garden, please keep animals and small children away from it! And don't EVER use it as a Christmas tree!