RERUN: Canada's National Tree

Since today is Canada Day, I figured I should either do a post that has to do with this great country, or at the very least re-post the blog I did last year on this day. Last year's blog it is! A new blog post continuing the "Sandra's Garden" theme will be coming shortly. To keep you tied over until then, enjoy this post from Canada Day last year about the differences between sugar maples (our National tree) and Norway maples (an invasive species). Happy Dominion Day!

Species names: Acer saccharum, Acer platanoides

Common names: Sugar maple, Norway maple

Location: Ontario

Since one of these trees is native and the other is not, and there's a reason why one would be featured more prominently over the other on a wonderful day such as today, I put up the photo for a native species.

Since today is Canada Day, I figured I should probably feature our national tree, the one proudly flown every day on our flag, the sugar maple (a species that I didn't quite do justice to in this blog post). Unfortunately, the Norway maple has become almost as common as the sugar maple in Canada (if not more common in some areas) because it is, for some obscure reason, planted in preference over our native species. Perhaps it's because it doesn't succumb to the native sugar maple pests that we have, but it was also the reason why we have periodic outbreaks of the Asian longhorned beetle, its primary pest, which is decimating forests across the country. The other downside of the Norway maple is that it produces phytochemicals from its roots that deter understory growth (including grass, if you choose to plant one in your front yard), and when fully mature it can inhibit the growth of native species of trees and shrubs in a forest to such an extent that you sometimes find "Norway maple oases" where nothing else exists.

So how can you tell the difference between a native sugar maple and an invasive, non-native Norway maple? The key is in the leaves. First, if you've got a purple maple tree in your front yard you've got a Norway maple. Sugar maples have never been bred to have purple leaves, so that's a great place to start to be able to stay away from the Norway maple. Second, take a look at the lobes of the leaf, specifically the top lobe. Does it have deep groves running almost halfway down the leaf, separating the top lobe from the ones on each side of it? Or is the lobe very shallowly separated from the rest of the leaf? Shallow lobes are Norway maple leaves, deep lobes are sugar maple leaves. If you look at the second picture (sugar maple on the left, Norway maple on the right), you can also see that when you compare them side-by-side the number of teeth along the leaf's edge also differs quite a bit; the Norway maple has quite a few more teeth along each lobe where the sugar maple doesn't. Third, take a look at where the petiole (or the "leaf stalk") branches off into the main veins of the leaf. Are these veins approximately the same colour as the tissue of the leaf, or is there a drastic difference in colour? As in the third picture, veins roughly the same colour as the leaf is seen in the sugar maple, drastically different leaf main vein colouring is characteristic of the Norway maple. The last and most easy method for telling the two species apart is by breaking a leaf off the stem and looking to see what happens. Is there a white milky latex that oozes out of the petiole? Or is the base of the petiole dry? The Norway maple is the one producing latex, the sugar maple doesn't (and that latex can be irritating to the skin, so be careful!).

Now you know how to tell the two trees apart. And not to leave out my American friends, the sugar maple is also the state tree of New York, West Virginia, Vermont and Wisconsin. All four of those states have impeccable taste in trees! :)

Happy Canada Day!

Look what I got!

Species name: Euphorbia milii

Common name: crown of thorns

Location: my office!

Yesterday was the annual plant sale here on campus and usually I get a few tomato plants and maybe an herb plant or two for my mom's and my lame attempt at growing our own food (tomatoes seem to dislike us, yet we valiantly try growing them every year...). This year I got some cherry tomatoes and some "prize winning" tomatoes (don't let me down, now!), as well as some clove basil and purple basil (tried both of them; both taste like regular basil). I also saw this gem of a plant there and wanted to snap it up before anyone else got the chance. Understandably, carrying it back to my office was a bit of an undertaking but at least everyone steered clear because they didn't want to be impaled. I have to give special thanks to Jason my office-mate who gave me $0.50 of the $2 purchase price to buy the plant for our office; he is the proud owner of 1/4 of everything you see in the images.

Hopefully you read my blog often enough to know I've blogged about a variety of this plant already during my series of "Plants of the Dominican Republic". If not, what's wrong with you?! Get reading! :) (just kidding; you can find the blog post HERE). So just as a refresher, this plant is native to Madagascar where its native habitat is threatened, and is incredibly toxic from all parts of the plant so extreme care should be taken when handling. I'm glad I knew that already; no one told me that at the plant sale...

So what's exciting about this plant? I mean, aside from the physical attractiveness of the plant itself. Sure, it's a little evil-looking with its giant spines but the flowers are beautiful and the leaves are an awesome colour of bright green. But the other reason why these plants are great is because of the propagation potential: growing a new plant from a stem cutting from an old one is almost idiot-proof. You wait until the plant goes dormant and just looks like a giant stick of spines and cut pieces off. On the original plant the cut point will result in a branching of the plant (so shaping plants is easy simply by pruning), and the cutting can be used to generate a new plant. You wait a few days until the cut end starts to callus over, then put it in a pot with slightly sandy soil. Water once a week, but make sure you let the soil completely dry between waterings or else the cutting will likely rot. Remember that these are succulents; the fastest way to kill the plant is by watering it too often!

BLOG UPDATE: Last weekend I was at my friend Sandra's house helping her out with a garage sale (since I absolutely LOVE garage sales!). The sale itself was less than stellar, probably because it was darn cold on Saturday morning, but Sandra's garden is full of strange and unusual plants. When the sale wasn't busy I wandered around taking pictures of plants in her garden with my iPhone, and will be featuring a "Plants of Sandra's Garden" series over the coming weeks on my blog.

When a flower isn't a flower: part 2

Species name: Euphorbia pulcherrima

Common name: poinsettia

Location: Dominican Republic

The poinsettia, an incredibly popular ornamental plant as both a landscape plant in tropical locations and a potted plant in temperate locations, is native to Mexico and Central America. It is, contrary to popular belief in North America, a tree that can be up to four meters tall. A bit big to fit in a pot! Like many euphorbs, poinsettias do incredibly poorly in pots and shed their leaves quite quickly. This can be due to over- or under-watering, but usually is just a case of the plant being incredibly picky, and not being able to tolerate the short periods of sunlight that it does receive during our winters (8-10 hours of sunlight in a very sunny window versus the 12 hours of sunlight it would receive near the equator), and the temperatures that are much too cold (it prefers to grow at temperatures that average 25 degrees Celsius; much warmer than "room temperature" in the average house in North America during the winter!). This tree in the Dominican was significantly taller than I was, and while it was rather sparse on the green leaves it had enormous clusters of bright red flower bracts, or modified leaves.

Yes, that's right. Poinsettia "flowers" aren't real flowers. Sorry to disappoint you! The true flowers are illustrated in the bottom picture, and even at that they're not fully in bloom yet. The flower buds are the very small greenish pink knobs on the inside of the bracts, and will eventually open into either yellow or white flowers. They are incredibly inconspicuous even when fully open, and do not produce nectar and hence don't attract pollinators (even hummingbirds ignore the bright red bracts). The flowers are, instead, wind pollinated. The bracts also aren't always red, contrary to what we picture the typical Christmas poinsettia to be. They can also be orange, yellow, pink, white, green, and a mottled colouration, usually of pink and white together.

There is quite a bit of speculation about the toxicity of poinsettias, and parents who have "been there" are usually the first to warn you about how deadly this plant is. Well, let me tell you: all lies. Yes, if a small child ate one of the red bracts (or even a green leaf, or chewed on a stem) they would be quite ill with diarrhea and vomiting if they consume sufficient quantities, and learn never to do that again (albeit the hard way). In an analysis of over 26,000 supposed poinsettia poisonings, none resulted in death and only two required hospitalization (likely a hypersensitivity reaction). All were as a result of children and accidental ingestion. Some studies have looked at just how many leaves one would have to consume to die of the latex produced in the bracts, and the results are overwhelming: a 50 lb child would have to eat 500 bracts to require hospitalization due to risk of death from poisoning. That's a whole lot of poinsettia leaves, and I think the real question there if it ever happened would be how a child could get ahold of 500 bracts and be left alone long enough to consume them all. Sounds more like neglect than accidental poisoning! So will having a poinsettia around Christmas potentially kill a curious child? Absolutely not. You should still ALWAYS educate children about putting foreign plant parts in their mouth, because some houseplants are absolutely lethal enough to children to cause death upon consumption, just not this one. If they play with the bracts too much and release too much sap, the latex will cause skin irritation, rashes, itching, and in some children with hypersensitivity reactions to latex, hives. A word of caution: the jury is still out about this plant's toxicity to cats (it has the same reaction in dogs as it does in humans). There are an over-abundance of cases of cats dying as a result of eating poinsettia leaves, and perhaps some of them are true. But I have my doubts about the majority of them, considering how benign they are to humans (I'm guessing the cat probably got into something else that was in the house that led to the cat's death, but that's just speculation). Better to be safe than sorry; if you have a cat, make sure your poinsettia is out of reach to it (perhaps a tall order...literally) or you are vigilant while your cat is around the plant.

The association of the poinsettia to Christmas in the United States and Canada was merely a marketing ploy by a family in California, and a very successful one at that. The plants require a special grafting technique to merge two different species together in order to get the typical bushy plant that you see on store shelves in pots. If left to their own devices, poinsettia plants end up getting rather strange-looking and weedy, as demonstrated in the photos above. Once grafted, they look much more pleasing to the eye. But how to get those red bracts? Because those certainly are not "natural" when grown in North America...or is it? In Central America, because of the 12-hour days, all of the terminal branches have bright red bracts. In order to achieve this, the plants must be exposed to 12 hours of consecutive darkness for two consecutive months, with the other 12 hours being uninhibited sunlight. If any more or any less darkness reaches the leaves, they will stay green (or the plant will just plain old die) and the plant won't be all that attractive. This is the other reason why poinsettias never do well indoors in pots; rarely are they put in rooms that receive total darkness after sunset. I don't know about you, but I like turning on the lights in my living room after dark! The Ecke family business no longer produces poinsettias in California as they had since the early 1900s, but now produces them in the plant's native Mexico. They still serve 70% of the North American market for poinsettias around Christmas. In Mexico, however, this plant has special meaning. The flower bracts radiate outwards like a star, and is said to represent the Star of Bethlehem. Legend also has it that a young girl in the 1600s was too poor to provide a gift to Jesus on his birthday, and instead gathered weeds to lay outside the church. After a few days, poinsettias started to grow and the plants have been incorporated into Christmas celebrations ever since. While not a national plant, it is a very important culturally-significant plant in Mexico.

For part 1 of this blog, about the flower bracts of the bougainvillea, please read the blog post HERE.

If the spines don't get you, the latex will!

Species name: Euphorbia milii var. splendens

Common name: crown of thorns, Christ plant

Location: Dominican Republic

The crown of thorns is native to Madagascar, as are many species of Euphorbia. There are an estimated 100 species in the genus, but I have my doubts that they all belong. There seems to be a group of about 40 species that are native to Madagascar (some are critically endangered, some or more common but all are at risk due to habitat destruction), another group that are native to mainland Africa, and then yet another group that are native to Europe and South America (to see an example of the morphological variation in the family, read all about the chenille plant HERE). The plants native to Madagascar are very similar to the one pictured above; small-ish brightly-coloured flowers, very thick green leaves that are concentrated at the tips of the stems, long spines, and are relatively low to the ground. The ones native to Africa are trees; some can be up to 35 feet tall but otherwise similar to the Madagascar euphorbs. The plants native to Europe and South America are the weird ones; they're the round, "blobby" euphorbs that look absolutely nothing like their African "relatives". It wouldn't surprise me at all if there ended up being multiple genera within Euphorbia and a lot of renaming of species in the years to come. There are currently four sub-genera, but even those don't quite seem to be natural groups, at least to my untrained eye. I'm going to lay my bets on there actually being six genera within Euphorbia. We'll see if I'm right; I'll re-evaluate this blog if there's ever a genus-wide systematic DNA analysis that's performed.

The crown of thorns is a species that has a rather unique common name, due to its hypothesized role in Christian and Catholic beliefs. The story goes that when Christ was nailed to the cross, he was also forced to wear a crown made of a very thorny plant; whenever there's a painting depicting Christ's crucifixion, his head is always bleeding from the thorns digging into his forehead and scalp. It is believed based on geological evidence and stories passed down through generations (as well as artifacts discovered in Mosques and in underground burial tombs) that this plant was transported to the Middle East very early on; as many as 5,000 years ago. The story goes, then, that this plant is the source of the thorny branches that made up Christ's "thorn crown" during the crucifixion. The story of Br'er Rabbit, Br'er Fox and Br'er Bear courtesy of Disney also revolves around a dense thicket of thorns (I only know this because of the ride Splash Mountain at Walt Disney World in Florida...), and it's highly likely that these are some sort of euphorb (the story is based on folk tales told by African slaves after first being transported to the United States, so its doubtful the plants making up the Brier/Briar Patch would be American species) or other African spiny species.

All euphorbs are highly toxic. Some are more irritating only to the skin, while others produce noxious fumes from their latex (the white milky substance that is released when any part of the plant is damaged, as you can see in the third picture) and can cause severe respiratory problems. If ingested, this species won't kill you but will most definitely make you sick (vomiting, diarrhea and severe dehydration as a result of these two). African species can cause death just from contact with the latex, let alone ingestion. It's amazing the kinds of defence systems that some plants have evolved! Unsurprisingly, it is rare to find any kind of insect or other animal herbivore munching on these plants as a snack.

The flowers of this plant are quite neat, and you can actually gauge the age of the flower bracts by their colour. What we see as "flowers" aren't actually flowers at all. The two "petals" are modified leaves called bracts that contain chromoplasts instead of chloroplasts, which give the bracts their red to pinkish hue. These bracts change colour as they age, and the rate at which they change colour depends on the amount of sun they're exposed to and how long the bracts have been fully-developed. They usually start off a bright pink or red, then gradually fade to completely green before the fruit is mature, then the bracts fall off. Those small yellow patches on the very inside of the flowers are the true flowers; the fruit of these plants is rarely larger than a few millimetres across and is red when mature.

Probably not the chenille you want to knit with

Species name: Acalypha hispida

Common name: chenille plant

Location: UWO Greenhouse

The chenille plant, also called the Philippines Medusa and the fox tail, is native to a set of small islands off the coast of Australia, between Australia and Indonesia. It has now been domesticated throughout much of the world with a warm climate year-round (it is not frost-tolerant) such as the southern United States, Mexico, Brazil, and Belize. It is still common throughout all of its native range, and much of its naturalized range.

The chenille plant can almost be considered a domesticated plant in some areas. It no longer does well in the wild in some spots it has been introduced because we (as humans) have subjected it to artificial selection to favour traits we like. The inflorescences, while usually having quite a bit of "fur" on them, were much shorter and much less hairy in the wild ancestors than the ornamental varieties sold today. This is considered artificial selection as this would never have happened naturally in the wild; increasing the hairiness of the inflorescences actually decreases the plant's ability to disperse their seeds. Not a good thing if you're the plant! There are also some cultivars of ornamental plants that have orange and even yellow inflorescences as opposed to the "natural" red colour (but this has also been artificially selected for increased intensity).

The family that this plant belongs to is called the Euphorbiaceae, or the spurge family (sometimes the euphorb family). The easiest way to determine if a plant belongs to this family is if it produces a milky white latex from the leaves when they are broken (which you can see dried on the leaf's surface in the third photo). If so, chances are much higher it belongs to this family than not. If you have sensitive skin like I do, you'll also probably find out the hard way that euphorb latex is extremely irritating to sensitive skin, completely separate of whether or not you have a traditional latex allergy. This should probably suggest to you that perhaps this plant shouldn't be consumed if it has the ability to burn your skin on contact, and you would be correct. The chenille plant is deadly toxic to small animals, and would make any human that tried to eat it very sick. If you have cats, you might want to reconsider before buying this plant (either to plant outside or as an indoor plant); my cat would mistake the inflorescences for cat toys in a heartbeat and it would likely be a deadly mistake.