Mexican White Pines are better than our own White Pines in our own climate?!

Species name: Pinus ayacahuite

Common name: Mexican white pine, ayacahuite

Location: Western University campus

I have my suspicions about this tree, and it has nothing to do with the identification. There are three Mexican white pines all planted in a pretty clump; they are definitely ornamental trees and were planted after the arboretum was established on campus (so, believe it or not, these trees are younger than I am. Boy do they grow fast! Because...I'm not that old, no matter what my students would lead you to believe). They are most definitely Mexican white pines. What I have my suspicions about is their distribution and abundance. They are native to three very, very small pockets in Mexico along parts of the mountain range that runs straight through the middle of Mexico. These three pockets are now independent populations, and at the time of their assessment under the IUCN (the International Union on the Conservation of Nature) the three populations were non-interbreeding. This in itself isn't necessarily a big deal, but it's the rest of it that matters. Mexico is undergoing, like many countries in Latin America, a huge shift from rural rolling landscapes where you won't see a person for miles into a highly urbanized country with extensive urban sprawl. On top of that, all of these "Eco Resorts" are popping up all over the country. And then there's the drug running (there's no point in denying that it exists!). Oh, and on top of all of that the conversion from traditional vegeculture multi-crop agriculture to a more "North American" (I hate that description for it, since Mexico is part of North America) method of monoculture agriculture. These four things in combination amount to a lot of deforestation; doing this in an area that already contains three highly fragmented populations of a species, populations that exist nowhere else, probably means that the "Least Concern" status that this species has according to the IUCN is now incorrect. I would bet that at least one of those three populations no longer exists, and that the status of the species should, at minimum, be category NT or "Near Threatened", if not VU or "Vulnerable." But, as with all biodiversity research, you first need to find an organization that will fund the research to go out and study these populations (which hasn't been done since 1994!). To say this is a "Mexican problem," or even a "Third World problem," would be completely incorrect. Under the current economic climate in Canada, the only species reassessments done for species at risk are for species that grow in economically significant areas (like the Tar Sands in Alberta), or in areas where urbanization is slated to occur (in the case of Environmental Assessments). I like to think that Canada is a pretty "developed" country...!

Not having the funding to do diversity studies and study species distributions isn't something that can be restricted to a specific geographic region. It's something we, as human beings inhabiting the world, need to think about. Where are our future medicines going to come from? Nearly 95% of medicines around the world are plant-based or plant-derived (or once plant-derived but now synthesized in the lab). Many of our most successful early cancer treatments originate from plants (taxol is the first one that jumps to mind, and you can read all about the plant that taxol comes from HERE). Our most widely prescribed (and most would argue, for good reason, over-prescribed) antibiotic comes from a fungus (penicillin from the Penicillium fungus). And where would we be without wine (grapes and an alcohol-fermenting fungus) or tequilla (agave and an alcohol-fermenting fungus)?! It would be a sad case indeed. Anyway, onto happier things, like talking about Mexican white pines... :)

The Mexican white pine is one of the most widely planted pulp trees, from which we derive paper. Nearly every large paper-producing country in the world (except Canada) plants the Mexican white pine as opposed to any other white pine species. This is because it is highly disease-resistant (especially to white pine blister rust, which is an ever-increasing problem in Canada and the United States, attacking all of our native white pine species), highly cold-tolerant (despite being from tropical Mexico, it can withstand temperatures of -30 degrees Celsius!), and highly drought-tolerant. This makes it ideal for planting in hot, dry countries, hot, wet countries, cold, dry countries, and cold, wet countries. Name a country that doesn't fall into one of those categories! I dare you :) Because of their large cones, and soft, feathery needles they are also a highly prized ornamental species. One great thing about this tree that makes it ideal to plant as an ornamental is that it doesn't actually get to be that large. The tallest Mexican white pine on record lives in Germany and is only 20 meters tall. That's not a very big tree for being the biggest ever recorded!

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!

A Northern coffee relative

Species name: Cephalanthus occidentalis

Common name: buttonbush

Location: Ontario

Buttonbush is a native plant to North America from southern Ontario all the way south to Mexico. There are two, perhaps three, clear distinct populations of buttonbush. One population occupies a range extending almost completely down the eastern seaboard of North America, from Ontario east to Nova Scotia all the way south to Texas and east to Florida. A second population occupies the fragment of the native range in Mexico (these two populations don't overlap in area, but can very easily still interbreed). A third population exists to the west of the Rocky Mountains in California. The fact that the native range is now so fragmented suggests this species was at one point much more abundant than it now is. It also suggests that those two populations (the Mexico/eastern North America population and the California population) are now undergoing the process of speciation because of the huge geographic distance that is between them.

My blog readers in warmer climates (or those who have been to warmer climates and have gone out and appreciated some of the local species grown for agricultural purposes; Ethiopia, Colombia, Peru, Ecuador, Jamaica, Cuba, Dominican, Mexico, Venezuela, South Africa...) might recognize some features of this plant while finding others completely foreign and not looking like they belong (a somewhat similar story to the oak-leaved hydrangea, which you can read all about HERE). The leaves of this plant look strangely similar to those of the coffee tree, while the flowers (and later, the fruit) look completely different. Well, you're on the right track! This is one of the northernmost species of the Rubiaceae, or the coffee family. Other important species in this family are the madder plant (a very important plant in the natural dye industry; the dye obtained from the madder plant is a brilliant red), cinchona (important for the alkaloid extract quinine, important in the treatment and prevention of malaria), and woodruff (important in the production of coumarin, and profiled on my blog HERE).

Like many native North American plants, the buttonbush has a historical medicinal use for Native North Americans. The bark of the plant was used like a tea (and sometimes chewed when it was young and fresh) to treat diarrhea, rheumatism, headache, fever, toothaches, and (of all things) venereal disease. Whether or not it is medicinally valuable against many of these conditions remains to be seen, but it is useful on the skin to relieve itch and various skin rashes. One of the types of rashes that it is most effective against is the skin rash associated with an allergy to the essential oils of the poison ivy plant. Conveniently enough, where the buttonbush is most common is where there is usually a high density of poison ivy plants. It's nice that natural remedies to some of nature's most toxic plants grow right beside the offenders!

Most medicinal effects this plant may or may not have have been abandoned since this plant is actually quite toxic. It contains a chemical called cephalathin, which causes vomiting and, in severe cases, can cause convulsions and paralysis. Consumption of this plant is highly discouraged, even though many other species rely on it for food (birds, bees, deer, rabbits, waterfowl, and shore birds).

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."