BLOG RERUN: Happy Diwali!

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

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

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

Common name: marigold

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

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

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

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

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

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

Sandra's Garden: This hawkweed has spots!

I've been sitting on this blog post for a couple of days because I've been really unsure of the correct ID for this species. I was pretty sure I had it once...but then changed my mind. Then I was pretty sure I had ID'd it correctly again...but then changed my mind again! Now I've got it. I think. If you think I'm wrong, feel free to point it out in the comments section and lead me to a more appropriate name. This is one of the reasons why I hate trying to ID "dandelion-like flowers"--they're just so gosh darn hard to get the right name if you don't have a microscope and a full identification key handy!

Species name: Hieracium maculatum

Common name: spotted hawkweed

Location: Sandra's garden

This species of hawkweed, incredibly common throughout Europe where it is native, is also now becoming more and more common in Canada. Here it's considered a weed since it thrives in highly disturbed areas which include that garden you just dug up to plant new flowers, or the area around where you just cut down the tree and don't know what to replace it with. In Sandra's case it's growing right beside her driveway (made out of gravel, not asphalt), but it's also serving as a great example of what the definition of a "weed" is: a plant that's growing somewhere where we don't want it. Sandra's got a great philosophy towards gardening: "if I like the plant, then it gets to grow." While most of us would have ripped this plant out a long time ago because it looks far too much like a dandelion for our liking, Sandra lets it thrive behind a rock that serves as a buffer between the driveway and the mulched garden. Enjoy your time while it lasts, little plant!

Hawkweeds are some of the most successful plants in disturbed areas because of the way they reproduce: they make asexual seeds. This phenomenon is incredibly unusual overall in the plant kingdom, and when a plant decides to reproduce asexually (which in itself is actually quite common) or clonally it rarely chooses to do so via seed production. Rhizomes, tillers, offsets or offshoots, suckers, foliar embryos, splitting, layering--all of these are common phenomena displayed in various plant species (sometimes even in groups as large as families) that rarely results in a seed-like structure being produced. In fact, plants that reproduce asexually prefer to do this over reproducing sexually but yet retain the ability to do so if growth conditions change. Reproducing asexually is much faster than producing seeds, and seed production is very energetically taxing on the plant (sometimes even killing the plant afterwards!). On top of that, you never quite know what kind of gene combination you're going to end up with since you shuffle all of your genes and they are randomly distributed (along with your mate's genes) into the seeds; each seed still gets one copy of each gene (or two, or four, depending on the plant...) from each parent, but each parent can have two different copies. Which one your offspring gets (you might have two good copies, one good and one bad copy, or two bad copies) is luck of the draw. Why would you risk giving your offspring a bad copy of a gene when you can just pass on all of your genetic material, exactly as it is, to your offspring so they can thrive like you do in the environment you're in? Seems like a no-brainer. But when the environmental conditions change and you are challenged as a plant in your environment, you might decide it would be best for you to roll the dice and take a chance at shuffling your genes so your offspring have a better chance in this new environment. Thus, seed production. But ASEXUAL SEEDS? This just seems crazy.

And for some plants, deciding whether to produce asexually or sexually is way too much work, and since your gene combination works for you it should also work perfectly well for your offspring, aka your clones. Almost the entire genus of Hieracium species reproduce exclusively via asexual seeds that are dispersed in the same way that dandelion seeds are in the wind; this process is called apomixis. This leads to the debate of "what is a species?" which is currently getting quite heated between experts that study this plant in Europe and in the United States. Some say that each clone should be considered a different species, since if you don't reproduce sexually it's impossible to tell who is your closest relative (a perfectly valid argument; one that has been raised in many other plant, animal and fungal species). That would give us about 10,000 species of Hieracium. Others argue that species should be defined based on broad morphological differences, which would give us about 800 species of Hieracium. Just a little difference! No matter which way you choose to define species, I think it's safe to say that there's a lot of them. If you tried counting to 800, it would take you a while; that's my definition of "a lot." There are a lot of species of Hieracium. There. Problem solved!

So what are hawkweed species good for? Absolutely nothing (sorry for just getting that song stuck in your head)! Actually, the plants themselves and the seeds are important food sources for a lot of animals, but one moth in particular: the large yellow underwing moth. This insect species is a great example of an insect that is expanding its range in response to warmer, shorter winters. Prior to the mid-1980s it was found exclusively in Europe and the Middle East, but after its introduction to Nova Scotia by accident in 1985 it has spread all the way to California and Alaska in 20 short years. Prior to that it had never been found further north than the southern edges of Russia! A pretty incredibly feat for a bug.

Inside the Spider Room of Doom

Species name: Paphiopedilum sp.

Common name: paph orchid, orchid

Location: UWO Greenhouse

Ah, orchids. The bane of my existence. OK, not really. But I know they would be if I ever attempted to keep one alive; I can just see it ending in another botanical murder. I admire them in greenhouses, not on my desk.

Orchids are a rare (actually, not so much...) and wonderful group of plants. There are actually several hundred groups of plants that we refer to colloquially as "orchids", the Paphiopedilum being just one of those groups. These are commonly called the "lady slipper orchids" due to their shape. This plant of unknown species name (it is probably a hybrid) is one of about 80 species in the group, and is native to the tropical rainforest somewhere in Southeast Asia. Each species in the group is native to a relatively small range within that broad geographic area, but hybridization events readily occur at the boundaries of the species ranges. This would (and rightfully should) raise the question of "so are they really different species if they can hybridize?" Good question! I would say no, but obviously I've been overruled by a couple of centuries of botanists significantly more knowledgeable about orchids than I am!

The greenhouse at Western grows a huge variety of orchids, all of them being a bit different. They might be completely different species (and in some cases, in different groups within the orchid family) or just different hybrids or cultivars, but most of them are just named with their genus and the species is left undetermined. I was going to do a whole series of blogs about "the orchids of the greenhouse", but all of the plants are in what I call the Spider Room of Doom where, you guessed it, a ridiculous number of spiders live in all corners of the room because it's so hot and humid. Anyone who knows me knows that I hate insects, so going too far into that room is out of the question. What? I'm allowed to have rules. :)

Orchids are a fantastic group of plants for two reasons. The first is because of the cumulative native ranges of all species of what we consider "orchids". This native range actually stretches from pole to pole, all the way around the globe. To me, it's absolutely incredible that any one group of plants has managed to completely master the ability to live in literally every ecosystem around the world. They are by far not the most dominant species in any one ecosystem (in fact, most species of orchid around the world are critically endangered either due to wild hunting, climate change, habitat loss, or a combination of all three), but they're present. The second reason why orchids are so amazing is because of their flower shape. There are some orchids that mimic wasps and bees, some that mimic birds, others that mimic pheromones ("sex hormones") of insects, and some that absolutely reek, all in an attempt to attract one specific pollinator. In fact, orchids are a fantastic example of co-evolution: when the single species of insect that pollinates the single species of orchid changes in some way, the plant changes with it to rope it back into (in a sense) their mutualistic relationship. It's an evolutionary arms race to ensure the partnership of both species!

For all you caffeine addicts...

Species name: Coffea arabica

Common name: coffee

Location: UWO Greenhouse

I was contemplating skipping this plant and blogging about it later when I finally found my pictures of wild coffee plants growing in Cuba, Dominican and Jamaica, but then decided that no, I'll just make it two blogs! Ah, the joy of being my own boss...

Despite coffee being grown in multiple locations around the world (with Colombian coffee gaining the most press recently as being the most prolific source of the world's coffee), it is actually incredibly rare in its native habitat in Ethiopia. There are some protected natural populations, and some equally protected populations in neighbouring South Sudan (no one is quite sure if that is a native population or a population that was introduced there very early on in the domestication process). There is also one very old population in Kenya, but it is believed to have started there as a result of trade with Ethiopia hundreds of years ago and not an independently domesticated population. Due to climate change, the "growable range" of coffee is shrinking. It requires cool, humid climates usually on mountain sides. There have been many attempts to grow coffee in North America in the great outdoors, but every single one of these ventures has failed. Coffee is very sensitive to rainfall, and if it is in an area with too much or too little rainfall it will not survive. To say it's a finicky plant would be an understatement! It is possible that with further climate change the Rocky Mountains or the Alps might one day be hospitable for coffee growth, but by then we will have significantly more problems than just not having coffee!

Believe it or not, the British used to be avid coffee drinkers, not tea drinkers. So what happened? Well, one of the areas of the world during the British Empire that was the most productive for coffee was Sri Lanka, then called Ceylon. Unfortunately, there's a fungal pathogen of coffee called the coffee rust that was spread from Ethiopia into Yemen and then to Sri Lanka that completely destroyed their coffee crop since it had no resistance (native populations do have some resistance to this pathogen; we have also now developed fungicides and genetically modified crops that show much higher resistance). The British noticed that the Chinese and Japanese made a beverage very similar to their coffee drink, and decided to "borrow" some of their crop to replant Sri Lanka. The British had discovered tea, and have been tea drinkers ever since (and tea is still the leading export of Sri Lanka, even 400 years later!). Tea and coffee, the main sources of the drug caffeine, are the most consumed beverage around the world. One could argue that caffeine is also the most abused drug in the world!

One of the Austrian pines

Species name: Pinus nigra

Common name: Austrian pine, European black pine

Location: Ontario

The Austrian pine is native to Europe, in countries surrounding the Mediterranean and Baltic Seas. There are actually two subspecies of the Austrian pine which rarely interbreed (but are still capable of forming hybrids in a very small overlapping zone as well as when they are brought together under artificial conditions like a greenhouse): the western subspecies existing in southern Italy, southern Spain, southern France and North Africa and the eastern subspecies in Austria, central Italy and Turkey. The needles of the two subspecies are quite different and you can easily tell them apart when side-by-side; the needles of the eastern subspecies are much fatter and much more rigid than the western subspecies. They both have different liveable temperature ranges, too, with the eastern subspecies being able to tolerate much colder minimum temperatures (down to -40 degrees Celsius with no adverse effects) compared to the western subspecies (only about -25 degrees Celsius or so). I believe the subspecies on campus would be the eastern subspecies, P. nigra subsp. nigra.

One major attractive feature that probably led to its widespread planting across Europe and North America is that it is a very fast growing tree, relative to other needle-bearing trees. It was originally thought to be an excellent lumber tree, so it was planted in large numbers in North America. Unfortunately, the grain of the wood is very rough and quite variable across the height of the tree, so making long boards suitable for building is not feasible. It was turned to as a major source of pulp and fibres for making paper, as a fuel source, and is still used as a low-grade wood for some construction purposes.

Unfortunately, as with most plant species that have been transported out of their native range, the Austrian pine has a dirty secret. That secret is a fungus. The "red band needle blight disease", caused by the fungus Dothistroma septosporum, is especially toxic to North American Austrian pine trees because of their inability to breed properly here. Austrian pines have a hard time cross-breeding outside of their native ranges, and the seeds that are self-fertilized are much less likely to germinate. This causes something called "inbreeding depression," which can lead to a buildup of genes that make a tree (this happens in animals, too) more susceptible to a pathogen. The North American trees are very susceptible to this pathogen, and it is an almost certainty that every single Austrian pine tree in North America will succumb to this disease. There is no known treatment once a tree is infected other than cutting it down and burning the residues (especially the needles, where the pathogen is housed in the living tree). Planting this tree, even as an ornamental, is strongly discouraged and planting this tree in continuous stands is not only strongly discouraged, but carries quite a hefty fine if you're caught doing it in many states in the United States (but no provinces in Canada yet). You can see that the tree in the top picture is looking very unhealthy; it is likely showing the first signs of infection from the disease.

Happy Diwali!

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

Common name: marigold

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

First of all, I would just like to address the third image, and the fact that Wiki now has a flower alphabet meant to teach children not only how to identify flowers, but also teach them the alphabet and how to read. Are you kidding?! Way to go, Wikipedia! I am SO impressed. With that out of the way...!

Today is the first day of a five-day celebration by Hindus, Sikhs, and Jains in India and around the world. It is known as the "festival of lights" or Diwali (or Deepavali, depending on what part of India you're from). I tried following how the exact date of Diwali is determined for any given year, but got lost after the mention of lunar days. For us non-Indians, it's sometime between mid-October and mid-November. This year it happens to be on November 13th. So how does this relate to a blog about plants, when it's a celebration of lights? Well, read on...

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

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

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

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

The Canadian beer-tree

Species name: Ptelea trifoliata

Common name: hoptree, wafer-ash

Location: Ontario

The common hoptree or wafer-ash (named after the wafer-like fruit that persist on the tree until the following spring) is a rare species in Ontario, but the native range of the species doesn't extend far into Canada. Species become less and less common towards the limits of their range (whether the northern edge or the southern edge) since those habitats are less ideal than towards the centre of their range. There is the potential for this species to become more common as the climate changes, but there doesn't seem to be anywhere for this species to expand northward.

This species belongs to the Rue family, or the citrus family. It is the northernmost species of this family on any continent. When the young twigs or leaves are bruised or ground, they smell distinctly like lemons or oranges. Fantastic! The fruits look similar to the hop fruits normally used to flavour beer, and when used for that purpose the fruit of this species give a similar flavour (and hence the common name). The trees themselves rarely actually look like "trees," as in the first image above. The branching occurs very close to the base of the tree, giving it more of a bush-like appearance. For this reason, it's not a popular ornamental tree species, but would fit very nicely in a location meant for a shrub (but they can grow to be 8 meters tall under the right conditions!). They are not ideal for providing shade, since the branches don't fill out well towards the top of the plant. They're very..."sticky."