Thursday, May 30, 2013

Sandra's Garden: non-Canadian Canada Redbud

Species name: Cercis canadensis

Common name: Canada redbud

Location: Sandra's garden

Canada redbud is, contrary to the Latin name and the common name, not really all that native to Canada. As an aside, neither is Canada thistle...

The native range of Canada redbud extends from a negligible amount in Southern Ontario south to Florida and Mexico, west to Texas and Oklahoma, and east all the way to the coastline and up to New England. The native range map of this species barely registers a blip in Canada, and yet we plant it here in large numbers as an ornamental species. It will never do as well here as what it does in Kentucky and Tennessee (do they call it American redbud there, I wonder?), but it does well enough to still be spectacular in the spring. The flowers form directly off the largest stems and branches of the tree (sometimes only being big enough to qualify as a shrub) in huge numbers, and almost all of them will develop into pods of seeds that look a bit like brown snow peas. The leaves are a bright green and a heart-shaped.

This was surprising to me, but Canada redbud seeds and pods are actually edible, and have been eaten by native North Americans for centuries. The unripe immature green pods can be eaten raw, and the ripe seeds of brown pods can be roasted and turned into a coffee-like beverage (without the caffeine, and probably without the tasty flavour) or eaten. The flowers were also eaten either raw or boiled. I can't imagine either of these being all that tasty, but I guess when you have nothing else to eat you'll eat anything that won't make you sick! The toxicity of raw Canada redbud plant organs has never been tested, so I don't recommend anyone tries eating the pods or flowers raw. But give some roasted seeds a try if you're feeling adventurous and let me know what you think. The twigs themselves have also been used as a flavouring; the young green twigs would be rubbed against and skewered into venison or buffalo steaks before cooking to give them a somewhat spicy flavour (and hence the other common name for this plant, spicebush; use this name with caution since it is applied more commonly to another species).

Other than the obvious ornamental use, this plant isn't really used for much else. The trees never really grow large enough to produce lumber, and the overall shape of the plant (the main stem is rather short and it forks very early in growth; the best lumber trees are very tall, very straight unbranching trees) makes it impractical for anything other than making veneer; even at that, the grain isn't all that attractive so other species are more preferred. The tree can tolerate everything from full sun to full shade (but does best in full sun to partial shade). They also provide a great nectar source for native bees, butterflies, and some birds!

Wednesday, May 29, 2013

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.

Wednesday, May 22, 2013

A monster looms in the bluebells...

Species name: Taraxacum officinale

Common name: dandelion

Location: Ontario

Feeling like you have deja vu? That might be because I've already blogged about dandelions before, but they were regular ordinary dandelions. This one is special! If you'd like to read my last blog about dandelions and learn a whole bunch of cool stuff about dandelions in general, you can do so HERE.

Dandelions are most likely native to Eurasia, but there's a significant debate about their origins. There have even been a few people to suggest that the true dandelion that carries this species name is only found in North America, and that there's a separate species in Europe. The Europeans always feel they have to be special... :) Regardless of the true species name, almost all dandelions are created equal: they flower in the spring when you're just trying to get your grass looking good again, most people hate them, they have taproots that are nearly impossible to get out of the ground unless you're weeding after a heavy downpour and the ground is wet (if you've never weeded after it has rained, give it a try. You'll thank me later. You're welcome), they have bright yellow flowers that turn into fluffy seed heads, and no matter what kind of biological warfare you use on them the always come back. You know, typical boring (some might say ugly, but I rather like them) dandelions.

Except this one!

Instead of just talking about why dandelions are cool, I wanted to talk about why THIS dandelion is cool. You can see right away from the top image, highlighted in the bottom two images, that the flower head of this particular plant doesn't look like a typical dandelion plant. This phenomenon is called "fasciation", and so this dandelion plant is fasciated. This means that all of the flower heads that would have developed into their own flower under normal conditions have, for some reason, fused together and created a mutant giant flower head (caused by the fusion of many separate meristems at the end of the inflorescence stalks). This, to me, is one of the most fascinating phenomena of the plant world, and has been documented in over 100 species of plants. The best part? No one has any idea why this happens in any given plant. There are lots of ideas of why this might happen in general: exposure to radiation, attack of a virus, exposure to low doses of specific chemicals (like 2,4-D, or Roundup, for example), mechanical disturbance, insect damage, or genetic mutations. But could anyone tell you why THIS PLANT became fasciated? As of our current knowledge, no. You could definitely speculate and come up with the most likely scenario but you would never be 100% sure (and there are likely other reasons why this happens that are currently undocumented). Normally this phenomenon is incredibly rare in the plant world, and to see it would be a real treat...except dandelions. Apparently dandelions do this all the time! Silly plants. The speculation here is that in this plant species it is more than likely pre-determined by genetic mutations that can be passed on through the seeds, but also exposure to common pesticides like 2,4-D also play a role (and dandelions are always on the end of chemical attacks, it seems!). Unfortunately, someone ripped this plant out of the ground (and by someone, I mean the people that do grounds maintenance on campus) before it had a chance to finish flowering and turn to seed. I would have loved to continue taking pictures of the flower development and collect some seeds to see if I could grow a new fasciated dandelion! Yes, I know what's coming. "You know you're a nerd when..." :) Don't worry, Mom and Dad. I would have done it in the greenhouses at school!

Have you ever seen a fasciated plant? Now that I know it exists, I saw the remains of a fasciated tulip growing in a bed on campus. Fascinating fasciation!

EDIT: I guess I should mention that this phenomenon isn't just restricted to the plant world; it also happens in fungi. Next time you're in the grocery store and have some time to kill, go pick through the bin of shiitake mushrooms. I bet you'll find a mushroom with a single squashed-looking stalk with two caps on the top. Fasciated shiitakes are quite common; I guess that makes the shiitake the dandelion of the fungus world!

Sunday, May 19, 2013

Breathe in, breathe out...

Species name: Pulmonaria officinalis

Common name: lungwort, Our Lady's Milk Drops

Location: Ontario

Lungwort is probably the most common wildflower across all of mainland Europe, where it is native. It exists in every country except for Norway, has been naturalized in Britain, and has spread as far east as Russia and as far south as Iran. It's one successful little plant! Aside from being a wildflower native to Europe, it is also a very common European garden plant which is why it is now found in North America; it was introduced here in the 1700s by European settlers to decorate their gardens and has thrived here ever since. This plant isn't quite successful enough in North America to be considered invasive since it reproduces very, very slowly from seed. Once established, it spreads like a weed through underground rhizomes. We have quite a patch of it growing in our garden. Sure, the flowers are nice and the flower early in the spring when everything else still looks dead, but too much of it is not a good thing. Plus, it's a non-native!

Lungwort is a great example of a principle called the "Doctrine of Signatures". This principle states that if a plant looks like part of the body, it can be used to treat that part of the body. This idea might seem a little crazy (which it is), but this explains where we get a lot of the common names of plants, and even some Latin names: "Pulmonaria" means lungs, and the Latin epithet "officinalis" (or any derivative of that word) means medicine. Any time you see a Latin name of a plant with that epithet, you know it was once used as a medicinal plant (and sometimes still is).

The flowers of lungwort are a great example of "magic" that can happen inside a plant when you're not paying attention. When the flowers first open they are pink, sometimes even almost red. This is because of an anthocyanin-based pigment found in the flowers that reacts to a very low pH by producing a colour that our eyes interpret as pink. As the flower matures, the plant gradually shifts the pH of the flower petals to be significantly more alkaline, sometimes shifting the pH as much as 5-6 points on the pH scale. This causes the anthocyanin pigments to change configuration, and instead of producing a colour that we interpret as pink, our eyes see it as blue. This change in flower colour is similar, yet different to the change in flower colour that can be observed in hydrangeas (which you can read all about HERE). Hydrangeas react to the pH of the soil, which in turn affects the colour of the flowers (as opposed to this flower colour change being plant-directed). The other difference between hydrangea flower colour changes and the changes observed in lungwort is that lungwort is more a direct reflection of the way we think of colour change according to pH: blue means basic, red means acidic. In hydrangea flowers, the colour indicates the opposite (very brightly-coloured blue flowers mean a very acidic soil and bright pink or red flowers mean a strongly basic soil).

So what kind of medicinal uses does this plant actually have? Well, it's currently used as an herbal medicine to treat asthma. This treatment is surprisingly successful; extracts from the plant are now being looked at as an alternative medication to asthma inhalers. Since people with very severe asthma start to notice a "desensitization" reaction occurring with the most commonly prescribed asthma medications, it would be a welcome addition to the market!

Thursday, May 16, 2013

The afternoon primrose

Species name: Primula sp. (a garden hybrid of unknown origin)

Common name: primrose

Location: Ontario

Primroses are another great example of why I hate common names. The evening primrose (profiled in a blog post that you can read HERE), is completely unrelated to species in the genus Primula, also called primroses. Sure, they look a little similar (perhaps not the evening primrose compared to this garden hybrid, but some other Primula species), but that's about it. Species of primrose in this genus are native to a wide variety of locations on almost every continent (Australia seems to be excluded from the list) but with the vast majority of the species in the genus native to the Himalayas. Since this garden hybrid (which is actually quite commonly grown) has an unknown parentage, meaning the two or more species that were hybridized to create this cultivar, so I decided to play it safe and call it a non-native species.

I think this species illustrates the concept of a weed perfectly. There is no real definition of a "plant weed," nor are there truly good examples of weed species at least in the common sense of the word. A weed is simply a plant that is growing in a place that we don't want it growing. A plant that is purposefully planted in one garden might be their next-door neighbour's weed. You can probably guess that most weeds are non-native species, only because those are the plants that are most likely to out-compete their neighbours since there are no pathogens to keep their populations in check. This primrose is a great example of a weed in our garden. I have no idea who planted it in the neighbourhood, but one spring it all of a sudden showed up. I ripped it out, but not until after it had gone to seed so now it comes back every year. I wish if it was going to grow it would do it more quickly and make a nice little patch of it that we could put a fence around to keep it contained, but it seems to like being the size that it is (about 10 cm x 10 cm and 4-5 cm tall). I'll refrain from pulling it out this year and see what happens.

I don't think it should come as a surprise to any of my faithful blog readers that I'm a bit of a skeptic when it comes to classification of species. This is probably because of the results I've found in my own work: apparently we're not very good at defining species of fungi at all, and many things that we thought were "species" are only morphological variants. Even more numerous is the trend the other way: many things that we thought were morphological variants are actually species. It's amazing what happens when you start to sequence a group's DNA and analyze the relationships between species! The genus Primula is a great example of this. There are over 500 species in the genus, some of which are so drastically different morphology-wise (and even habitat-wise, which should tell you something about their evolutionary relationships...) that I find it incredibly hard to believe they're in the same genus. With a more thorough investigation of these 500 species and a comprehensive analysis of the group's evolutionary relationships, it wouldn't surprise me if Primula ended up being divided into 25 or more separate genera. Might even be a fun post-doctoral fellowship... :)

Internationally primrose species have been used as medicinal plants for centuries. In fact, they have so many uses that they just might be a miracle plant should all of these uses prove to be effective in clinical trials. The roots of the plants are prepared in either a salve or a tea to treat any kind of cough (pneumonia, bronchitis, common cold, emphysema, etc.), the leaves are used in a tea to treat any kind of head-related ailment (dizziness, headache, stroke, sleeplessness, paralysis, etc.) and the flowers as a vitamin supplement (rumoured to contain high amounts of vitamin A and vitamin C) as well as any kind of digestive-related problems (diuretic, spasmolytic, and sedative). That's a whole bunch of uses for one tiny plant! I find it hard to believe that it could be effective against everything that might ever ail you, but you never know. With a species diversity in the genus argued to be at 500 species, if each one had a single use that's a whole lot of uses! It's also a good example of a general rule in botany and "plant gathering as agriculture": don't ever eat anything or use something as a medicinal plant if you're not absolutely sure about the intended use. If you use the wrong primrose, your headache might turn into a dizziness spell or convulsions!

Monday, May 13, 2013

The last of the palms: Otto von Bismarck's tree

Species name: Bismarckia nobilis

Common name: Bismarck palm

Location: Dominican Republic

Well, we have finally come to the end of my images from Dominican Republic, and this is my last plant species to profile from my lovely vacation in February (I can't believe these pictures have lasted me until May! I need to go on vacation more often...). I figured since it's the last one, I should probably go out with a bang...

The Bismarck palm is native to, like almost all palm species, Madagascar and is declining in numbers there (like many, if not most, of their endemic plant species). The fertile land is being cleared and converted to agriculture, with a few select trees being saved to represent landmark "specimen trees" throughout the landscape. Bismarck palms can be incredibly long-lived, have enormous canopies if given enough space, and provide great shade and habitat for other species. By leaving even just a few Bismarck palms, Madagascar is potentially saving tens of species who use these trees as refuge. Unfortunately, agricultural crops are worth far more money to the economy of Madagascar, and these trees likely don't stand a chance of sticking around for long. It's a shame; a country that was once one of the most biodiverse locations in the world is now becoming a barren agricultural landscape. I know I've poo-poo'd on Madagascar in a few blog posts, but the more people know about their biodiversity crisis the more that can be done about it. World economies really need to start putting pressure on countries that house the most diversity to stop cutting down forests because the species themselves have some sort of economic value. It's a slippery slope once you put a price on diversity, but it's true what they say in the business and commerce world: Money talks. Fortunately for the worldwide population of Bismarck palms, they are planted in huge numbers around the world as ornamental species (in the tropics and sub-tropics; they can actually survive temperatures as low as -6 degrees Celsius for short amounts of time). There are two main varieties of this tree: the green kind that's pictured above, and a variety that is almost blue because of a very thick layer of wax that is deposited on the outside of all of the leaves (which you might guess would be much more tolerant of drought and cold snaps; you would be correct with that assumption).

Bismarck palms are some of the most easily recognizable palm trees in the entire world...once you know what you're looking for. They have characteristic fan-shaped fronds with a very thick petiole connecting the leaves to the trunk of the tree. These petioles, as you can see from the image with the pink arrow, are curved presumably to allow the fronds to sway from side to side but prevent the snapping of the fronds if shaken up and down (since we all remember from elementary school that an arch is much stronger than a straight line...right?). This also provides a really unique habitat for animals, other plant species, fungi, and even bacteria since all of the rain that the fronds catch is funnelled down the petiole towards the trunk of the tree. Because the bases of these petioles are so warm and moist, they usually rot right off the tree before the leaf has a chance of dying, especially in very warm, wet areas. The inflorescences produced are also quite characteristic, and look a bit like marine ropes emerging from the base of a leaf. These mature into flowers (some male flowers are pictured in the 8th image; you can tell because they are full of stamens and very little of anything else), which either produce pollen or ovules. These trees, like the pacaya palm (which you can read all about HERE), are dioecious meaning one plant either produces male or female flowers but never both. The trees with the female flowers end up producing the fruit, which starts off green when immature and ripens to be yellow or brown (you can see the green fruit in the bottom image). The fruit are not reported to be edible by humans, although I'm sure someone somewhere has tried them. These are the preferred fruit of some birds and other animal species, so these trees do play an integral role in the food webs of the ecosystems they're living in.

I keep mentioning that these trees are integral parts of their ecosystems, so I think it's about time to show you what I mean. In the two pictures below (the same image, the first one is unaltered and the second one has a bunch of boxes around interesting features) you can see symbiotic plants and animals all living in the same tree:

The green and yellow boxes show the fruit of the Bismarck tree: the green box shows the immature green fruit and the yellow box shows the more mature yellow and brown fruit. Inside the pink box are three different species of plants, the heart-shaped leaf vine, the oval-shaped weedy plant, and the roundish-shaped weedy plant. What these species of plants are I have no idea; they were about 15 meters in the air and I wasn't about to climb the tree to find out! There are also a whole lot of sticks at the top of the tree, which is weird (in the purple box). In fact, I'm guessing that's the way those three plant species managed to make it up into the top of that lone tree; there are no trailing stems or roots to suggest that they "climbed" up there. In the orange box we have a lone bird, who seems to just be hanging out on an old petiole of a leaf. But is he really?

Well, Mr. Bird there isn't actually just hanging out on a petiole by chance; he's protecting his nest. Yes, that massive thicket of twigs was more than likely made by that ridiculously tiny bird (you probably are aware of the species; we call them "that brown bird that makes all the noise at 5 am during the spring" and this common name probably reflects about 500 species of bird). In fact, we stood under the tree for a while and watched more than one of these little brown birds fly to and from the nest; there's likely a whole family of them living up there. In hindsight, it was probably pretty stupid standing under the tree staring up at them (not that I'm afraid of a tiny brown bird or anything): if you're really observant you'll see white patches all over the underside of the palm fronds. Those aren't patches of fungi. Those are patches of "bird paint."

Here's another example of plant species that exploit this tree. Again, I have no idea what species this is since they're just tiny seedlings, but these are growing from seeds that would have been blown down those arc-shaped petioles and landed at the base of the leaf where there is likely an accumulation of organic material that is damp and warm: perfect conditions for plants (amongst other things) to germinate. These plants likely won't last long being squished into a petiole like that, but depending on what species they are they might be able to complete their entire life cycle without ever leaving the protection of their host plant. If those are species that are perennials or require much more space to grow, they'll likely die before producing anything substantial.

And, like I promised in my first blog post about pictures of plants I took while in the Dominican Republic, lizards also call this tree home. These pictures represent what is likely two different species of anole lizard (Anolis spp.) that are in all likelihood native to Dominican. If you think about it, these trees are absolutely perfect habitat for lizards to hide from predators in the petiole hollows, build nests at the bases of petioles, and jump from leaf to leaf to catch bugs to eat. They were pretty curious as to what I was doing holding a camera so close to their home; I guess I did neglect to ask them permission to photograph their treehouse. Next time I'll make sure to bring "lizard waivers" with me!

I hope you've enjoyed the rather long series about "Plants in the Dominican Republic" over the last few months! 

Friday, May 10, 2013

"I've got a lovely bunch of..." revisited

Species name: Cocos nucifera

Common name: coconut palm

Location: Dominican Republic

If you think you've seen this before, you're partially correct. I have blogged about the coconut palm before, and you can read about it HERE. This was before I had really decided what I wanted my blog to become, and when I took the photograph that I used I certainly had no idea it would one day become a blog post. I figured it would be fitting while I was back in the Dominican Republic to take a new set of photos of a coconut palm and do this properly. So here it is!

The location where the coconut palm is native is currently a heated debate. There is pretty strong evidence that the tree originated around or near the Indian Ocean, since many of the uses of coconuts date back to ancient times in India. There's also more to it than that; there are also fossils from the Eocene period, 35 to 55 million years ago, in Indian rocks that depict species strikingly similar to coconut palms (these are also found in Australia). To complicate matters, coconut palms have also been used for centuries by various groups of people in South America, and there are fossils there, too, that depict coconut-like fruit in rocks that are even older than the Eocene period. So who wins? I'll let one of the experts decide that; I'd rather not have either India and Australia mad at me or all of South America :) Regardless, it's not native to the Caribbean and yet is one of the most important crops there.

Coconut palms require very unusual conditions for growth and germination of their seeds (coconuts are really seeds!). First, they have to be exposed to tremendous amounts of sea water. This helps rot away some of the hard fibrous outer husk to reveal the inner seed coat. This coat then needs to be cracked, either by the growing plant or through the natural abrasion of coconuts crashing in the waves against rocks, in order for the new plant to establish itself. The growing conditions are equally unusual: they require full sunlight, very hot temperatures, high humidity, sandy soil, and high salinity. None of these conditions on their own are very conducive to plant growth, and when you add them all together it's miraculous the plant can grow at all. When you consider the habitat in which the seeds are deposited, this should be a no-brainer that coconuts have evolved to tolerate and thrive in these conditions. They thrive on hot sandy beaches where the ocean is ready to take away the coconut fruit, transporting them along ocean currents to a new beach where they can crack open and establish themselves.

Aside from their obvious edible uses, one of the most exciting uses of coconuts is in the medical field. "Medical field?!" you say? Yes, the medical field. Coconut water is gaining popularity as a sport drink to restore electrolyte balance in the body. Does the average person need to drink it? No. Just like the average person has absolutely no use for the high-calorie and high-salt beverages bearing the names "Gatorade" and "Powerade." High-performance athletes like professional athletes or people on high-performance teams absolutely DO require some sort of electrolyte replacement. Nothing will replace your lost body water than water, but if all you're drinking is water while sweating buckets for 2-3 hours (in some cases 5 or 6 hours, depending on the sport) you're going to start feeling dizzy and get muscle spasms. This is your body trying to tell you that you're losing too much sodium and potassium (amongst other things) to be sustainable and it needs more. Enter: sport drinks. These are absolutely chock-full of salts and sugars (as well as some complex carbohydrates, but those are by far fewer in number than sugars) to replace what you're using and to give you a short burst of energy. "Normal" people who go to the gym for an hour a day definitely don't need sport drinks! So what does this have to do with coconut water? Well, it's been shown that coconut water has an almost perfect electrolyte balance in it that is in synch with what the body needs. Replacing your lost fluids, at least some of them, with coconut water is significantly more beneficial than a sugar-filled sport drink.

Now, you might be scratching your head and wondering how this was discovered in the first place and what sports drinks have to do with medicine. I always appreciate an inquisitive mind! Would you believe me if I told you that one of the first uses of coconut water in modern civilization was as a blood plasma replacement? Not only is coconut water completely sterile as long as the husk is intact, it also has that perfect body balance of nutrients and vitamins to be able to replace fluids lost through illness or massive trauma. During World War II it was mixed with blood units to dilute the blood (since it was so badly needed; they had to make what little blood they did have go further to treat more wounded soldiers) but still provide all of the benefits of blood plasma, then it was administered through IV to the wounded soldiers during surgeries. It can also be used as "IV fluids" either prior to surgery when the patient isn't allowed to eat food or drink liquid, or when the patient is having trouble keeping down food and water and requires replacement fluids. Coconuts aren't just good for making Bounty chocolate bars!

The last mysterious use of coconuts that many people know about but don't realize they do is as a commercial fibre source. These aren't fibres you can use to make clothing; coconut fibre clothing would feel similar to burlap if worn against the skin so I can't imagine that would be all that pleasant. Coir, what we call the fibre we get from coconut husks, is most often used as a matting material. Most of those brown scratchy "Welcome" mats you buy to put outside the door are made of coconut husks, as are a lot of the "fluffy" potting mixes that come with boxed bulbs like amaryllis bulbs. The "peat pellets" that you can buy at garden stores to start seeds indoors before transplanting outdoors are also often made at least partially of coir; they can be pressed into very small pellets and when put into warm water can absorb water and expand to be hundreds of times the original size of the pellet. It's actually a fascinating process to watch!

Thursday, May 9, 2013

The Pac(aya) Man tree

Species name: Chamaedorea tepejilote

Common name: pacaya, guaya, palmito dulce

Location: Dominican Republic

The pacaya palm, sometimes called the pacaya grande depending on where you're from, is native to Central America from Mexico south to Panama. It is one of the most common palms native to the Americas, second only to Washingtonia palms native to California (which are planted in massive numbers as ornamental palm species). Because they are so attractive, pacaya palms have been transported throughout the Caribbean for use as ornamental species, but you will rarely find them outside of the Western Hemisphere. Unlike many palms, this species is highly shade tolerant, and actually "sun intolerant". The leaves, as you can see in the image above, become yellowed and sunburnt very quickly when exposed to direct sunlight so they are best planted in the shade of other trees.

The variety of this tree most commonly grown as an ornamental species are types that "cluster," as opposed to single stems. In the wild, this is incredibly rare but in cultivation it's common. It leads to a much more attractive bunch of stems, as opposed to one tall and spindly stem. The other benefit of growing this variety is that it is much more resistant to hurricane damage, since it is more difficult to disturb a clump of plants all connected via underground rhizomes than it is to disturb one lone tree.

This tree is an example of one of the many palm species that are dioecious. This means that there are separate male and female flowers on different plants; this is exactly like with holly plants, where you will only have red berries produced on female plants if the male is present (which doesn't produce red berries). The determination of "sex" in a plant is quite different than it is in a human; instead of being determined by a chromosome like it is in humans (with human females being XX and human males being XY) and it's instead a cluster of genes on a chromosome. Certain alleles, or copies of the gene, determine either "maleness" or "femaleness". The plants pictured above are likely male; in the entire cluster there was no evidence of fruit being produced, which occurs during all months of the year.

The seeds when ripe are apparently edible, as are the flowers (with the female flowers tasting significantly better than the male flowers, apparently). I would highly recommend you avoid eating any palm fruit unless you are absolutely positive of the species identification; many palm fruits are deadly toxic. In El Salvador and Nicaragua, the pickled female flowers of this plant are seen as delicacies and are served only during special meals.

Wednesday, May 8, 2013

The shedding tropical almond tree

Species name: Terminalia catappa

Common name: Indian almond, tropical almond

Location: Dominican Republic

The tropical almond is a very large tree, reaching heights up to 35 meters tall, native to the warm tropical regions in Asia, Africa and Australia. This particular species (that common name applies to 6 or 7 species in the genus; one of the reasons why I'm not a big fan of common names) is native to India and surrounding area, reaching as far east as China and Thailand. It is planted extensively throughout the New World Tropics (the Caribbean Islands, and Central and South America) as an ornamental species. It was discovered that the seeds of the tree are edible once the very tough outer husk is removed from the fruit, and when this husk is added to fermenting sugar cane an amaretto-like beverage can be produced (and hence the name "tropical almond," not just for the appearance of the fruit which are pointed to by the pink arrow in the third photo).

I have seen this tree on every single one of my tropical vacations; I'm pretty sure I've even seen it planted in Florida. Normally to see an ornamental tree or shrub species everywhere isn't uncommon, since if it's pretty in one area it's likely going to be pretty in another area. But to introduce a species that sheds its leaves during the peak tourist season, as well as its fruits that often attack unsuspecting tourists, is just plain silly to me. You've got all of these thousands of species of native trees to tropical North and South America that keep their leaves all year round; why not use one of those?! For the entire week there were people pulling leaves out of the pool, since during the summer months this is a wonderful shade tree and so logically is planted in areas where shade is desirable.

Medicinally, this plant has been very popular in native herbal medicines around the world for a wide range of treatments: it has reported use in India and Suriname for dysentery and diarrhea, and in Taiwan for liver disease. Interestingly, this plant has gotten a lot of press recently because of the reported benefits it might have in fighting cancer. There are some chemicals in the leaves that reportedly act as antioxidants, but there have been no studies that have shown that this plant has any effect on cancer cells, either in the body or in petri dishes (from any species!). Should someone "prescribe" this plant to someone who has cancer or suggest they drink a tea prepared from the leaves it is highly unlikely to result in death, but don't expect it to melt the cancer cells out of the body. So far it's a fake cancer cure at best. It does have some proven health benefits, but only for a very narrow portion of the world's population. In a study that examined bark extract from this tree they noted that it has the ability to kill the plasmodium that causes malaria, even when this plasmodium displays resistance to all (or many) of the drugs we currently use to treat or prevent malaria. This is a very promising result for those who are diagnosed with (and who die from) multi-drug resistant malaria every year.

For those of you who are fish enthusiasts, you have likely been in close contact with this plant and just didn't realize it. The leaves can remove toxins from water, especially heavy metals that might be contaminating the water. They are used to condition water before it is prepared for fish inhabitants in aquaria. Also, it has shown promising activity in preventing the spread of water molds that grow on fish (usually called "Ick"), effectively reducing disease in fish populations. If you've ever purchased a betta fish (sometimes called a "Siamese Fighting Fish" in pet stores), you've likely purchased a fish that was treated with these leaves as preventative measure to ensure it gets to you, the consumer, disease-free.