Tuesday, July 30, 2013

Dr. Jane Bowles: a great botanist, friend, and mentor

Species name: Acacia tortilis

Common name: umbrella acacia, Israeli babool (in Swahili: mgunga, mugumba or munga)

Location: all photos from Dave's Garden (photo 1 by DMersh, photo 2 by DMersh, and photo 3 by palmbob)

You might be wondering why I'm featuring this plant in my blog today; for a full explanation you can scroll down to the bottom of this blog post past the next plant profile. Umbrella acacia trees are probably one of the first plants that come to mind when you think of Africa. They are for me at least! They have an enormous native range, reaching from the north all the way to the south of Africa and into the Middle East. When I think of the African savannah, this is by far the first tree (and sometimes the only tree; I'll be the first to admit that my African botany knowledge is quite limited!) that comes to mind.

The umbrella acacia actually looks rarely like an umbrella when grown in cultivation. Because it is so extremely drought tolerant, it is often grown in climates where the type of ecosystem that prevails for most of the year is a dry, sandy desert. Here, the umbrella acacia looks more like an acacia with a bad hair day, and is very straggly and wiry. It is only when the young seedlings are exposed to large amounts of rain that the trees end up developing into the typical umbrella-shape that is so characteristic of the African savannah. That, and grazing animals that force the tree into that shape couldn't hurt; this tree is one of the preferred food sources of giraffes. The "umbrella" of the canopy begins where the branches are just out of reach from the giraffes and everything below that point is eaten away. That's not the only animal that eats the umbrella acacia: humans have also used this tree as a source of gum arabic (added to many, many food items), and the seed pods are used for various herbal medicines. The seeds may be eaten by humans but are rich in tannins so are usually avoided (but may be used as a source of natural dye instead!), however other grazing animals like small mammals or birds eat these seeds as a rich (and rare) source of protein and fat.

There are quite a few products made from the wood of this tree, and is one of the reasons why it is grown so much in cultivation in Africa and the Middle East. The wood is very important for fine woodworking products like wagon wheels and furniture, as well as raw lumber for fenceposts and animal pens. The tabernacle, built by Israelites in the Old Testament, was also exclusively built from wood of the umbrella acacia so it has important religious significance as well. It also has very high significance to more than 20 different groups of people (either groups defined by language, linguistic dialects, country lines, or cultural beliefs), but the most important of which for the purposes of this blog post is that it's the National Tree of Kenya.

Species name: Stylophorum diphyllum

Common name: wood poppy, Celandine poppy

Location: Dave's Garden -- DaylilySLP

I think this is probably the only critically endangered wildflower species that I've ever personally seen in Ontario. When I saw it I didn't realize what it was or how important it was, so I didn't bother photographing it despite having my camera with me. Next time! There are only three populations in Ontario, which is the most northern part of its native range (which extends into the United States and is still quite limited; it is now only a small fragment of what it used to be), ranging in population size from 42 individual plants to about 270 individual plants (at last reassessment in 2007). It is a victim of land use change (converting forests to agricultural land) and invasive understory species (like garlic mustard, which you can read all about HERE), which continue to threaten the last three populations in Canada.

Wood poppies are similar to bloodroot, another native species which grows on the forest floor in southwestern Ontario (which you can read all about HERE), in that they produce a rhizome in their first year of growth, and use the sugars stored in that rhizome to produce leaves every spring. The rhizome of one plant isn't nearly as long-lived as in bloodroot, with the lifespan of the average rhizome only being about 5 years. The plant rarely produces flowers in its first year of growth (except in cultivation; it has become a popular garden plant over the last decade or so), so it is sometimes mistaken for other wildflower species during that first year. The seed pods that the plant produces are very unusual and are far larger than you would expect from a plant as small as this one (rarely growing more than 20 cm off the ground) and also share seed characteristics with bloodroot. The seeds are produced with a fleshy, fatty outer covering called an elaiosome which attracts ants. The ants take the small seeds and carry them away to their underground chambers where they use the elaiosome as a rich food source, then discard the seeds when they are finished. The seeds then germinate the next spring and grow up through the ground to produce new plants. This ant-plant dispersal relationship is called myrmecochory. Other animals, if given the chance, will also consume the seeds (seeds were found in great numbers in mouse droppings near one of the remaining populations in Ontario).

Medicinally, despite having close relatives that produce morphine and codeine, this plant has no value. It does contain some alkaloids that may prove useful in some medicinal sense in the future, but right now there is no documented medical use of this plant either currently or historically as an Native North American herbal medicine. The alkaloid cocktail in the plant is more than likely toxic to humans, so avoiding grazing on the leaves if you grow this plant in your garden would be strongly suggested. Wearing gloves when gardening around this plant is also suggested, as the sap from the plant may irritate sensitive skin.

Unfortunately, the fact that this plant is now grown in cultivation and the source of these plants is not a native source (which is actually a good thing; wild-harvesting of this plant in Canada is illegal and would be extremely detrimental to the few plants left in the wild) means there is now the risk of genetically contaminating the remaining plants. The populations in Canada had their DNA sequenced and compared to the US populations and it was shown that these three populations are genetically distinct from their American counterparts. This doesn't mean there was enough difference for them to be considered different species, but there was enough of a difference for it to be noteworthy. When the pollen of a foreign population mixes with the ova of a native population to make seeds, the foreign DNA from the pollen contaminates the native population, effectively creating "genetic hybrids" of both populations. Since plants in cultivation are usually much more susceptible to disease than their wild counterparts, this could be really bad news for our last three native populations.


So why these two plants, you might be wondering? Well, these were the two plants I could best think of to commemorate the loss of a great botanist, my friend and mentor, Dr. Jane M. Bowles.

Jane grew up in Kenya, and some of the stories she shared about her childhood there are out of this world and beyond belief for someone that has lived in Canada their whole life (can you imagine growing up with a lion living in your front yard?! Mind-boggling to me!). She went to school in England, then moved to Canada to complete her PhD in botany about sand dune ecology at Pinery Provincial Park. Since the completion of her PhD, Jane was an adjunct professor in both Biology and Geography at Western and, most recently, the curator of the herbarium and the director of the arboretum.

I first met Jane at the field station associated with Western when I was out there with my supervisor searching for fungi in the woodlot at the back of the property. My supervisor introduced Jane as the curator of the herbarium (assuming I knew what a herbarium was; I was thinking "herbari-what?!"), and we went on our merry way. It wasn't until a couple of months later that I realized that, aside from my supervisor, Jane would probably be the single most important person (well, aside from myself, too, obviously) involved in the successful completion of my PhD. I rely so heavily on herbarium loans to look at historical mushroom specimens that I would have been completely lost without her. Not to mention that Jane was universally loved and respected by all herbarium curators around the world; with her as my primary source of communication to other herbaria I would have no problem having a loan in my possession two, three, sometimes four times longer than the period of time I was actually given. If you think that's bad it's not; it's not unheard of to have herbarium loans for 10 years or more!

Over the last 6 years I would say that Jane and I had become friends. I always knew I could count on her to provide me with a laugh thanks to her biting sense of humour, I could count on her for a swift kick in the bum to get myself in gear when I asked for it, and give me some helpful tips on how not to lose my sanity along the way. I would also say that her love for plants inspired me to grow to love them (sorry for the pun...actually, not sorry. That was carefully planned!), too. She taught me about the importance of native species, and drilled into my head the dangers of invasive non-native species. She opened my eyes to a whole new world of Biology: being a naturalist, and helping preserve the world for what it currently is and not try to change it to be what we want it to become to "improve our life" (it's often too late when we realize that having a giant forest was perhaps a bit better than yet another strip mall...).

Earlier this year, Jane was diagnosed with cancer. On Saturday, July 27th 2013, Jane lost her fight at Victoria Hospital. There won't be a day that goes by where I won't think of her, not a week that goes by during the rest of my time at Western that I won't remember one of her tidbits she told me, and not a year that goes by where I won't be reminded of what an amazing lady Jane was.

Goodbye, Jane. May your memory live on, and may you continue to inspire young impressionable scientists such as myself to become one with nature forever.

Jane was known for her amazing artistic abilities; this is one of her drawings 
of the wood poppy, which she drew for her co-authored species status report 
(you can read the most recent version HERE)

Friday, July 26, 2013

An homage to the Royal Family

I know it's been a while; it's amazing how busy life gets during the summer during the "down time" (actually the busiest time for graduate students since undergrads are off for the summer and there's very few of us who have teaching duties during the summer; this means all of our time can be dedicated to research, or in my case, writing my thesis). 

Unless you've been living under a rock, you've probably heard all about the birth of the Royal Baby, and all of the hooplah that goes along with it. Some people on twitter are less than impressed about hearing about it all the time, but you know what? I don't care :) I think reading about how excited people are for the birth of the future King of England is awesome. Do you know why? It's happy news. People were overjoyed about hearing about the engagement of Will and Kate, then their wedding was just plain ridiculous with regards to how popular it was with people around the world, and now their first child (with a bunch of other special events mixed in the middle; us Canadians got all excited when they came on their first Canadian tour). Sure, there will be some people that will poo-poo when having to hear or read about the Royal Family, and they can poo-poo all they want. It is an opinion, after all, and everyone's entitled to their own. I, for one, love hearing about the Royal Family. I think it probably stems back to when I was a little girl dreaming about being Tinkerbell or Cinderella, and what little girl doesn't dream about being a princess at least once?! Even if they just dream about how much they would hate it :) I personally think hearing all about the Royal Family is a nice change from hearing about all of the sad and terrible other things going on in the world today.

So with that, prepare yourselves for a blog about (a very small part of) the Royal Wedding! Since I had not yet started this blog when Will and Kate got married, I figured a great way to get back into the blogging swing of things would be to pay homage to their relationship and the little bundle of joy they just welcomed into the world. Welcome to life in the spotlight, His Royal Highness Prince George Alexander Louis of Cambridge!

And without further adieu, a blog about...Kate Middleton's bouquet.

(image from HERE)

There are four plants featured in her bouquet: myrtle, Lily of the Valley (the most dominant flower type), Sweet William, and hyacinth.

Species name: Myrtus communis

Common name: myrtle

Location: Dave's Garden -- growin

The common myrtle is a very popular garden plant in Europe (it's just starting to become more popular in North America, especially in warmer climates) and is native to the southern European countries that border the Mediterranean and northern Africa. Because this plant flowers so late, it is popular in providing a splash of flower colour in the late summer months (as well as a source of pollen and nectar for summer pollinators) and the fruit for the birds and small mammals in the fall. It is very cold-sensitive, and requires protection from even a light frost so would be unsuitable for use as an outdoor ornamental in Canada.

This plant has a long history as a medicinal plant, with such legends as Hippocrates and Dioscorides swearing by it to treat sinus infections. There is, unfortunately, no evidence to suggest it actually has any effects on the body other than a pleasant smell, so don't get too excited. But both the leaves and the flowers were used and are featured heavily in decorative illustrations done by both Hippocrates and Dioscorides in their epic works. This still doesn't explain what it's doing in a wedding bouquet...

Myrtle flowers are also incredibly sacred to the Romans, as they were the flowers that represented both Demeter and Aphrodite. Further, a myrtle branch with flowers on it was often presented, before an olive branch "became popular," as a sign of peace and goodwill when welcoming new neighbours or new members of the family. From here, myrtle flowers have become important signs of unity and goodwill, two important qualities when it comes to joining two hands in marriage (no matter what kind of ceremony it is!). The specific plant chosen for the myrtle flowers is also significant to the Royal Family: Queen Victoria planted the sprig of myrtle she used in her bouquet in her garden, and every royal since then has taken a small clipping from this tree to use in their own bouquets. The cuttings are rooted and then planted alongside Queen Victoria's tree (I can imagine it would be a veritable myrtle forest by now!).

Species name: Convallaria majalis

Common name: Lily of the Valley

Location: Wolfville, Nova Scotia

Lily of the Valley is likely native to Europe and western Asia, although there's still the idea that it might have originated in North America (although this explanation is slowly losing ground). It is, however, a very common flowering plant here in the spring and has even become invasive in some areas, outcompeting our native bloodroot, trilliums, and other native spring wildflowers. I have blogged about this plant once already; if you'd like to read about it you can do so HERE.

This flower is rarely used in wedding bouquets because of its flowering time; the Latin epithet of the species name "majalis" means "flowering in May." Since most people don't choose to get married in the spring and instead opt for the summer, finding these flowers in July or August is incredibly rare. This, in turn, drastically increases the value of the flowers to such an extent that they have become one of the most universal signs of wealth in wedding bouquets. This idea, of course, goes hand-in-hand with the Royal Family and the Lily of the Valley has been an integral part of all wedding bouquets documented in photography and (before the invention of the camera) paintings except Queen Victoria that favoured snowdrops. Will and Kate were lucky; they probably got an extreme discount on their Lily of the Valley flowers since their wedding was on April 29th!

Species name: Dianthus barbatus

Common name: Sweet William

Location: Dave's Garden -- DebinSC

The flower commonly called Sweet William is a rather mysterious flower, because no one is entirely sure how it got its common name. There are many stories about how it refers to William Shakespeare, but also some stories about Prince William, the Duke of Cumberland as well as Saint William of York and William the Conqueror. Whatever the origins of the common name, the plant itself originates from southern Europe and across most of Asia.

As far as royal bouquets go, this plant is incredibly unusual to be included, but I'm sure you can guess why it was. Kate included this flower as a tribute to Will, a gesture that was picked up on by botanists across England long before the media started reporting on it. See, sometimes it pays to know your plants! In general, these are incredibly unusual to use as wedding flowers but they are also very long-lived (they can survive in full-bloom with no signs of wilting or flower decomposition for months after cutting) so make for great wedding flowers if you want a keepsake in your home. Pure white Sweet William flowers are difficult to obtain, and most have a slightly purple tinge to them like the ones pictured above. The pure white flowers that Kate featured in her bouquet are a relatively rare cultivar developed in England in the 1980s.

Species name: Hyacinthus orientalis

Common name: hyacinth

Location: Dave's Garden -- chrisw99

As far as hyacinths go, the specific cultivar or variety pictured above is quite stunning. The stamens have been replaced by petals, a phenomenon referred to as "doubling" (it appears as if the plant has doubled the number of petals produced for a fuller flower, when it reality the flower has become sterile through a genetic mutation). This type of mutation does happen naturally but is incredibly rare; it has been exploited for centuries by horticulturists for fuller flowers. The other benefit of this phenomenon, at least for those observing the flowers, is that because the plant has no chance of reproduction the flower doesn't die as quickly. Dead flowers are usually the result of the end of the production of pollen and nectar, and instead of putting resources into maintaining the petals the plant shifts its resources into producing the fruit. Since doubled flowers don't have stamens to produce pollen, this resource shift can't happen and the flower remains on the plant for a longer period of time. If you'd like to read a full blog about hyacinths, you can do so HERE.

Hyacinths, again, are rare as wedding flowers in general but a staple of all weddings and coronations for the Royal Family. Because of their very early flowering time in the spring, they too are rare and expensive to use in wedding bouquets during the most likely time that a wedding would occur. The use of hyacinths (especially for coronations) can be linked to King George III who insisted that the "royal herb strewer" should precede him for his entrance so he would be walking through the sweet scent of flowers and herbs. King George III reinstated this practice in 1820 for his coronation, and selected hyacinths to decorate the venue due to their intense sweet scent. I'm not sure of Kate's reasoning to include some white hyacinth flowers into her bouquet, but it could be a symbol of the "coronation flower boys" of years gone by.

Tuesday, July 16, 2013

A joy for travellers to see

Species name: Clematis x jacksonii

Common name: clematis, traveller's joy

Location: My house (London, Ontario)

Clematis plants are some of the most interesting plants to me because of their quirkiness and eccentricities. They don't follow the "aesthetic rules" that most flowering plants do, and that's definitely one of the things that makes them so cool. This species, a hybrid between two Asian species then hybridized again with a common garden species popular in the late 1700s in gardens in Europe (the history of this garden hybrid is unknown, but likely from Asian ancestors, too). Due to the fact that this plant is a hybrid it technically carries no weight according to the IUCN Red List of endangered and threatened species, but I can vouch for the fact that this plant is not likely to spread, nor is it likely to reproduce and escape from the garden. We moved into our house in March of 2006, and I've never witnessed this plant producing seeds (which are actually quite spectacular; they're like dandelions with a bad hair day). Not good if you're the plant, but great if you're the gardener that doesn't want to clean up after the plant!

The second image shows the twice-compound leaves, which branch twice into three. The leaves are produced oppositely on the stem (the purple arrow points to where the petiole, or the "leaf stalk", attaches to the stem and you can see that there's another leaf growing off the stem in the same place in the opposite direction), and each petiole divides into three at a single point (you can see the path the petiole takes in yellow). From there, the petiole divides into three again, and at the end of this division there are three leaflets (red arrows). Sometimes leaves can do some strange things and not obey the rules. Instead of producing a leaflet at the end of the petiole, sometimes the leaf turns into a modified structure for climbing: a tendril.

In general, there's a lot of misconceptions about "specialized" plant organs used to attach plants to houses or climb up support structures. Peas are well-known for their tendril producing abilities, and clematis vines should be, too. Clematis vines produce very little growth from their old stems; they much prefer just to send up new shoots from their rhizomes just under the surface of the soil. If you consider just how much this plant has grown in a single growing season, obviously the height of the vine would produce too much weight for the plant to handle on a skinny non-woody stem. To help hold it upright, tendrils are produced to wrap around support structures. These tendrils originate from the leaf, and if you cut straight through a tendril and make a very thin cross-section and look at it under the microscope you'd notice that a tendril has the structure of a rolled-up leaflet. Pretty neat! These tendrils have another secret ability: they respond to touch. Have you ever wondered why a tendril coils? It's not because one side is produced "smaller" than the other and so it spirals to compensate for the lack of space. It's actually the plant that senses a suitable object is touching the tendril and has been for long enough to provide support, and the tendril will start bending towards that object as it grows. If you're REALLY patient (and I mean you would give a saint a bad name with your level of patience) and have a lot of time on your hands, take a tendril that's grasping at something to curl against, and hold your finger against it for maybe 30-60 minutes. Try to move as little as possible, but a little movement is OK. After your hour is up, you can walk away and return to your clematis the next day. What happened to the tendril? I bet it will have super-coiled around itself and made a mass of curly tendrily mess. There was a signal that the plant received when your finger was against the tendril that said "SUPPORT!!! COIL QUICKLY!!!" and it responded--just too late to be useful. You've now manipulated a plant into reacting to your touch. Pretty cool! See, manipulating plants for your own amusement can be fun...

The flowers of this plant are also incredibly unusual. There are flowers that produce four petals, five petals, or six petals (the majority seem to produce five). If you think that all of the flowers just had six petals and some lost a few before I took pictures of them, I also managed to find one of each version that was just getting ready to open, so I can definitely exclude that as an explanation. Why does this happen? As far as I know there's no explanation. None. Completely stumped. Our clematis grows in the shade, so I thought perhaps it was just confused and suffering from a lack of sun (these plants definitely prefer full sun or at minimum partial sun to be most happy) but I just looked up pictures of the plant on Google Images and there are people growing theirs in full sun and noting the same phenomenon. Find an explanation for why this happens? Let me know! I've always been interested in learning about why this happens.

Other than their obvious ornamental value, some clematis species (there are over 300 of them) have been used in North America as medicinal plants for centuries. It was used to treat nervous diseases and migraine headaches, but don't get excited about the medicinal properties of the plant in your back yard. Most clematis species are highly toxic, and the sap that's exuded from cut stems is highly allergenic, is phototoxic (meaning it will cause extreme rash and burning when the sap on your skin is exposed to intense sunlight), and can cause internal bleeding if ingested. This plant is best used as an ornamental species and not a backyard medicine. It's also probably best to use gloves when pruning this plant; some people are more sensitive to the toxins in the sap than others, but always better to be safe than sorry. The phototoxic effect can last for years, despite washing the sap off your skin.

Thursday, July 11, 2013

The tree with the yellow wood

Species name: Cladrastis kentuckea

Common name: American yellowood

Location: Western U Campus, London, Ontario

First of all, I've decided after doing a whole series of blogs about Sandra's garden that I'm going to start being more specific with where I took pictures of the plants I'm featuring in my blog. Featuring GPS coordinates would be silly (especially of rare plants, plus you would all also know where I live since I feature plants in my back yard a lot) and impractical since I don't own a proper GPS unit, but "Ontario" is a bit too vague. So this is the first blog to feature a more detailed location description. Blog evolution!

The yellowwood tree is a spectacular tree to have growing in your garden: it grows quickly but not very tall (the tallest yellowwood in the world is only 27 m tall), has a broad reach with its branches to provide a large patch of shade, and has incredibly attractive flowers during the spring. Unfortunately, it has a few downsides, too. The tree trunk tends to branch repeatedly close to the ground to get a "multi-trunk" type of tree so sometimes pruning is required to get enough space under it to park a lounge chair. Also, when the flowers start to drop it literally looks like it has snowed under the tree. This isn't necessarily a bad thing; it's a lot of organic material going back into the soil to support the soil microbes living in symbioses with the tree's roots. A lot of gardeners think it makes their lawn look messy, and so this tree is sometimes avoided. This is a shame since the seed pods, once they start to develop, are a great oily food source for animals during the fall and into the winter. Since these seeds are a preferred food source, very few of them make it into the ground to produce seedlings. Good if you don't want your lawn to look like a yellowwood nursery, bad if you're a yellowwood tree trying to reproduce. This same phenomenon can't be noted throughout the tree's range, nor is that seen further south; it actually has the potential to become an invasive weedy tree further south than its native range so be careful where you plant one. It is native to the United States as the name suggests, to a relatively small area bordered by North Carolina, Oklahoma, Missouri, Indiana and Alabama. Due to habitat loss it is becoming increasingly more rare throughout its native range, so if you live in that area and have the opportunity to plant a yellowwood, do it!

Aside from their obvious aesthetic value due to their flowers, yellowwood trees have traditionally been very valuable species in the woodworking industry. Because of the multi-trunking phenomenon they can't be used to produce many 2x4s, but they have been highly prized amongst furniture makers for their yellow heartwood to use for inlays and sometimes veneers. Wood turners have also valued yellowwood for its ease of carving yet very dense wood. Some of the most famous guns in American history also have their gunstocks made from yellowwood, although many other species of tree were favoured for this purpose.

Monday, July 8, 2013

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.

Wednesday, July 3, 2013

Sandra's Garden: The Last One

Species name: Syringa vulgaris

Common name: lilac

Location: Sandra's garden

Lilacs are some of the most easily recognizable shrubs used commonly for ornamental purposes. They have large heart-shaped leaves (although, not all plants that have "lilac" as a common name have heart-shaped leaves...), purple to white flowers, and the flowers have *THAT SMELL* that you smell it once and you never forget it. To me, it smells exactly like Myrtle Beach in South Carolina because that's the first place I was ever made aware of the smell; I remember walking to the beach from the camp ground past what must have been lilac bushes and a pond with baby ducks and snapping turtles that would eat the ducks. Thankfully I never actually witnessed a duck being eaten or else it might have scarred me for life. But I feel like I remember there being pens that people would keep baby ducks in so the turtles couldn't get them. Maybe I'm just making things up...this was back when I was 5 or 6 years old. I can barely remember last week!

And back to lilacs. They are native to Europe, from Croatia east to Moldova and south to Albania and Bulgaria. They had been introduced to the rest of Europe centuries ago and lilacs are now considered naturalized to most countries throughout the continent. The earliest settlers to North America brought lilacs as ornamental species, and so they have also existed in North America for many, many years. They are also considered naturalized here (it's even the state flower of New Hampshire), and have very little chance of becoming invasive since so few of their seeds are fertile. Normally you'd think a plant wouldn't do very well in the wild if the majority of the seeds being produced wouldn't be able to grow a new seedling, but this is relatively common in ornamental species (especially shrubs) because of their history of domestication: it was recently discovered that lilacs are actually hybrids of two drastically different species. When you hybridize two species that are closely related sometimes you don't even notice a reduction in fitness (or a reduction in the number of viable seeds being produced, which is a reflection of the potential number of offspring a single shrub could produce, called "fitness"). When you hybridize two species that aren't closely related then usually this reduction in fitness is quite drastic, if the hybrid takes at all. This hybrid shrub was likely a natural hybrid when it was first produced, and was since propagated over time.

Pruning lilacs is an art form to make sure it keeps flowering. If you just whack off the entire shrub at ground level (strangely enough, a "hard prune" is recommended by most garden centres for lilacs at least once every three or so years), you'll get a very "spotty" flowering on your shrub; these plants flower best on old growth. If you're cutting it off all the time, you're eliminating the possibility of getting really showy lilac flowers in the spring. The other side to this story is that lilacs can grow quickly if in optimal conditions, and so they can get to be an enormous size if left unchecked for too long. Dead-heading branches where flowers have been after flowering but before developing seeds can remove the branch's ability to extend further while at the same time promoting flower growth in later years. Win-win! Something to keep in mind too is that lilacs flower best every other year. So if you get one bad year, don't fret! A good one is probably on its way the next year.

If you like the idea of a lilac but absolutely cannot risk having a non-native plant escaping from your yard into a natural area, you could always plant a "doubled" cultivar. These cultivars have been selectively bred to have their stamens (or the "boy parts" of the flower that produce pollen) replaced with petals, so there are eight petals in each flower instead of four. If a flower doesn't produce pollen it cannot produce seeds, so this is a great way of planting a lilac for the smell without worrying about the plant getting away from you.

Monday, July 1, 2013

Sandra's Garden: proof not all Phlox are created equal

Species name: Phlox subulata

Common name: moss pink, moss phlox

Location: Sandra's garden

Last year I posted a blog about moss phlox, a native species we have in our garden that gets a little out of control in really sunny areas. It's a species native to North America, and one that occurs relatively commonly throughout its native range in bright and sunny, damp areas (despite also being drought-tolerant). It is much more common in the United States than in Canada. I knew this species was a popular garden plant based on what I've read about it, but I had never seen any of the cultivars created in greenhouses aside from the "normal" light purple type. Well, here's a spectacular demonstration of the "hidden" morphological variation that some plants contain. This variety of moss phlox was not created in the lab, but is a product of controlled breeding. Despite this, you would never find this variety of phlox in the wild unless it escaped from someone's garden.

So how do we "create" morphological variation in plants that is not typically seen in the wild? The secret is some patience, and a lot of time on your hands (it helps to have a greenhouse because it speeds things up a bit). Natural mutations in the wild create different alleles, or copies of a gene, that can show different morphologies if they have a chance to be expressed. Most of these mutations are what we call "recessive", which means you have to have two copies of the gene in order to be able to see the effect. This is good for the plant if the mutation is detrimental, but bad for gardeners if the mutation is something we want to see. In order to increase the number of recessive mutations in a population you back-cross the plants (breeding a daughter plant with a parent plant), or force inbreeding (forcing a plant with the gene to pollinate itself; sometimes this isn't possible in plants). After enough generations, which can be anywhere from 10 to over 1000 generations to get a pure line, you have a plant that shows only the allele you want expressed. Most garden plants are created this way; you back-cross over a certain number of generations until you get the desired effect in nearly all seeds grown. A huge downside of this type of selective breeding and back-crossing is that you're decreasing the genetic diversity in a population by selecting the alleles you want expressed and eliminating all others. For most plants this isn't a big deal; the ones grown in gardens are hardly reflective of the population as a whole in most cases, and if a virus or fungus or bacterium evolved that could eliminate an entire population of ornamental plant because of the inbreeding and a lack of resistance it wouldn't matter much. You would replant the next year with a different variety and hopefully the problem is solved. The big problem occurs when we start doing this with crop species, as we have been doing for over 12,000 years. Corn, for example, is so susceptible to disease that it is completely unable to survive without human intervention (not to mention we have eliminated the corn plant's ability to disperse its seeds; this is a slight problem if you're a corn plant but a major benefit if you're a human wanting to eat corn seeds). Soybeans in North America right now are on the verge of a massive population collapse due to the fungal disease called the soybean rust. It has recently shown up in the southern United States and is attacking soybean crops that have all shown to be susceptible to the disease. We grow the same variety in Canada (bred to have an increased seed size with an increased oil store in the seed), but are only saved from the attack of the pathogen due to our much colder winters that the fungus can't survive. It's only a matter of time before an entire year's crop is wiped out which could be absolutely devastating to the North American economy.

The previous blog post I did about this plant (which you can read about HERE) mentioned the smell of marijuana that this plant supposedly has, and the drug busts that have occurred as a result of people innocently growing moss phlox and having the smell waft in the wind. I did pick some leaves and crush them up; if you use your imagination I guess it smells like marijuana. I have a hard time believing that it would produce enough of a scent to convince someone there's a drug op in their neighbour's back yard, and I also have a hard time believing that someone would mistake the smell of phlox for the smell of marijuana!

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!