Friday, April 26, 2013

Brief Hiatus

UPDATE: thanks to those of you that e-mailed me while I was away at the conference to tell me that my brain had already gone on vacation when I posted this blog. Yep, definitely won't be back on Wednesday April 1st because that wasn't a Wednesday, and this Wednesday is apparently May 1st. My how time flies! Whoops.

It's been a while, hasn't it?!

I just wanted to apologize for my brief hiatus and to let everyone know that it will continue until Wednesday May 1st. This week started the "Marking Essay Fun Times!!!!" party for one of the classes that I'm a Teaching Assistant for, and the marks are due on Wednesday. That, mixed with the fact that I'm at a conference all weekend means no time for fun and games! I know. It's a sad week.

But on the bright side, the weather has been wonderful these last few days, and will be all weekend! Well, unless you're somewhere where the weather is going to be terrible this weekend, and then sucks to be you! So go outside and enjoy life outdoors. Find your own plants to take pictures of! Tell me about them! And if you'd rather just sit and wait...I'll be back on Wednesday :)

Cheerio! Thanks for being patient :)

Saturday, April 20, 2013

It wouldn't be a good story if that was the whole story

Species name: Delonix regia

Common name: flamboyant tree, Royal Poinciana tree, flame tree (but not the true flame tree)

Location: Dominican Republic

Unfortunately, when my mom and I were in the Dominican we just happened to miss the best time of the year to view these trees in the Caribbean. I've included a picture at the bottom of this blog post to show what the tree would look like in full bloom, if we happened to see in sometime between May and September (although, it blooms at different times of the year in different countries). The flamboyant tree is native to Madagascar, where is is near-endangered. The last IUCN Red List had this species listed as endangered, but since then there have been concerted conservation efforts in the wild to not only protect this species but also to aid in the tree's reproduction and repopulation. These efforts have been mostly successful, but there is still "seed poaching" that occurs in the wild to supplement the ornamental tree trade. If you do buy this plant as an ornamental species (its flowers make it a very popular ornamental species), make sure you know the source of the plant and that it's not from wild seeds. Once introduced to an area in the tropics or sub-tropics it reproduces easily if the appropriate conditions are met, and can survive well in the wild as well. It is said to be naturalized in many countries in mainland Africa as well as throughout the Caribbean and in Asia. It isn't reported to be invasive in any of these areas, but even a slight shift in climate could lead to population explosion and it out-competing its neighbours. There's a fine line between a naturalized species and an invasive one!

The flamboyant tree produces brilliant orange, red and yellow flowers (depending on subspecies and cultivar or variety) before the leaves are produced. Once the flowers start to wither and fall off the tree, it invests all of its energy into producing the characteristic leaves of trees in the bean/pea family (or the Fabaceae): twice pinnately compound feather- or fern-like leaves (which can also be seen in the Kentucky coffeetree which you can read all about HERE). I traced one of the leaves of this tree in red so you can see just how large one leaf really is. When I was in the Dominican, this tree was in the process of shedding its leaves for the rest of the dry season, and it would regrow them in about May or June during the rainy season. Since it is salt- and drought-tolerant, it makes for the ideal Caribbean tree.

Fortunately for my blog, this isn't just an exciting tree because of its flamboyant flowers (which you can't even see! A let-down). This is what botanists call an exciting "specimen tree." A specimen tree is a tree that is unique and exciting on its own, regardless of what the rest of the species does. For one, this tree is enormous. Normally flamboyant trees reach a maximum height of 12 meters but normally they grow to about 5 meters. This tree has got to be about 10 meters tall; it's just as tall, if not taller, than the 3-storey building behind it. But that's not the only thing that makes it exciting. It's a perfect example of a micro-habitat. Hard to believe that a tree could be an example of a micro-habitat, but I invite you to walk around to the other side of the tree and tell me what you see.

The other side of the tree

Do you see what I see? It's a bit more obvious now, but that sure looks like a giant woody root running down the trunk of a tree. Could that possibly be a root?! Well, let's zoom in near the base of the tree and find out...

The base of the tree

Yep, that's definitely a root. So what the heck is growing off of that tree, and where is it coming from?! Roots grow in the ground, not out of leaves and down trunks!

The split in the trunk of the tree

Well look at that. There's actually another plant growing out of the trunk of the tree, where the main trunk splits into two. There would be just enough space in there that the rain would accumulate some sand and dirt that the wind blows on the branches of the tree, plus the falling tiny leaflets of the leaves in the spring, that if a seed happened to fall into that space it could germinate and grow for a while. Now, this plant didn't just grow for "a while"; it has actually been incredibly successful. But is that the whole story to this tree?

Wouldn't be a good story if that was the whole story!

Actually, there isn't just one plant growing in that tiny space. There are actually three different species (shown by the red arrows). The first is the one that's the lowest down, which sure looks like some kind of amaryllis or spider lily to me. Keep in mind that the first photo is as close as I could get to this tree, and I certainly wasn't about to climb it to get a good look even if I could get closer. So we'll just go with "unidentified lily-like monocot" for now unless someone else has a better guess for me! The second, marked by the upper arrow on the right hand side is also an "unidentified monocot", but I actually think I know what this one might be. I have a pretty strong suspicion it's a false bird of paradise (which you can read all about HERE) because of the arrangement of the leaves. Unfortunately for these two species, neither of them is going to survive long given the amount of space they have. Both of these species grow from either a bulb or a swollen underground stem called a rhizome; without a vast supply of nutrients from which to sustain their underground storage organs, the above-ground green parts can't survive. The top red arrow, however, points to a plant named the umbrella plant, named for its umbrella-like leaves. The species name of this plant is Schefflera arboricola, and is a very popular ornamental plant native to Taiwan. It thrives in tropical conditions, and can survive in very nutrient-poor soil. It also grows roots incredibly quickly (mainly due to the fact that they need to seek out what few nutrients there are in the soil), which is the contributing factor to the death of most umbrella tree houseplants (most of them become root-bound and the roots suffocate themselves in the pot). Thankfully for this species and its fast-growing roots, it can "escape" the death-trap that it found itself in (like the false birds of paradise and that lily-like plant) and anchor itself in the soil at the base of the tree.  The pink arrow indicates where the roots wrap around the branch and connect to the stem of the plant, showing that it really is all one plant. Eventually, if left to its own devices, the flamboyant tree will die and decay long before the umbrella tree. What will be left will be a giant hole in the middle of the umbrella tree where the flamboyant tree used to be, and it will look like it's standing on stilts. Fantastic! This creation of micro-habitats in the main branching points of trees in tropical forests is actually incredibly common; if you walk through a tropical jungle you'll notice a lot of "trees on stilts" where exactly this phenomenon happened over and over. If you manage to be the first plant that out-competes its neighbours for resources and hits the ground first, it's a fantastic place to be to avoid predators that want to munch on your bright green nutrient-filled leaves. They would have to be incredibly determined to climb a big tree to eat a seedling! There are far more of them on the forest floor that would make a better dinner.

The flamboyant tree in full bloom (courtesy of Wikipedia).

Thursday, April 18, 2013

Magical Tamarind

Species name: Tamarindus indica

Common name: tamarind

Location: Dominican Republic

Tamarind is a tree species in the pea or bean family that is native not to India but tropical Africa, and used around the world as a flavouring, a food, and a plant-based dye. There are actually many plant species used as "tamarind" flavouring, so if you want an authentic flavour to your food you need to make sure you get the right species! When ground, it's nearly impossible to tell real tamarind from the fake stuff, so always buy it unground to make sure you're getting what you're supposed to get.

Because the tamarind is part of the bean family, it does produce a pod that is the fruit of the tree, and the fruit is what is consumed. The very tough outer covering must be removed, revealing the reddish-brown squishy insides of the fruit. This can be mashed into a paste, and used in cooking. Depending on if the fruit is ripe or not the flesh on the inside has very different tastes: unripe fruit are very, very sour and used as pickling agents, and ripe fruits are much sweeter and used for flavouring main dishes and even desserts. Tamarind fruits are very, very good for you. They have very high levels of calcium in the ripened flesh, as well as surprisingly high amounts of various B vitamins. Both of these are unusual to find in fruits! My favourite use of tamarind is in a beverage; there is a typical Nicaraguan drink made out of chia seeds, lemon juice and tamarind juice that is this really odd brown colour and has slimy seeds floating in it. Sounds gross, looks less than appealing, but MAN is it ever good. I've tried re-creating it once but can't quite get the proportions right. I need a Nicaraguan friend to teach me how to make it!

Tamarind wood is also some of the most beautiful wood in fine furniture and other decorative products, with the heartwood (or the "old wood" on the inside of the tree) being a bright red without a stain. The sapwood is a reddish yellow, and stains much darker red when a "mahogany" stain is added. This wood is sometimes marketed as mahogany wood outside of Latin America and tropical Asia and Africa, but there is one major difference between tamarind wood and true mahogany: strength. The strength of mahogany trees is tremendous (and a "mahogany tree" doesn't really exist; like with tamarind, many species would be what we would call "real mahogany"), while tamarind trees are a bit wussy. If wood was needed for extreme strength like a bed frame to hold up a North American-style bed, this would not be your wood of choice. If all you're making is a decorative art piece and want dark red wood, this would be the wood for you! It looks amazing in jewelry boxes. While it can't withstand extreme weight, it is very durable and very dense wood so would be perfect for other furniture like tables and chairs. The ground fruit can also be used for another purpose in home decoration: it can be used to remove the tarnish on brass, copper and silver. Grind up some of the flesh of the fruit, apply to a rag and rub. When the patina or the tarnish is removed, rinse with water and you're done!

The medicinal uses of tamarind are long and also depend on the country that uses it. In Nigeria it is used to treat stomach disorders, in Indonesia and Malaysia it is used to treat malaria, in other countries in southeast Asia it is used to treat fever, and in India it is used to treat cardiovascular problems and digestive problems. Again, traditional Indian medicine (Ayurveda) is onto something with this plant; excessive consumption of this plant will lead you to notice its primary medicinal value: it is a very potent laxative. There are other claims that tamarind can delay the onset of the most severe symptoms of osteoporosis because it contains so much calcium, as well as claims it can reduce circulating levels of cholesterol. Neither of these have been shown to be true in human studies, but if you have a pet rat that you don't want to die of low bone density you could try feeding it some tamarind paste in its regular diet, and if you have a chicken you're especially fond of that doesn't watch what it eats, you could give it some tamarind paste to reduce circulating levels of cholesterol. Don't expect this effect to be translated into eggs; the yolks of eggs laid by chickens whose diets have been supplemented with tamarind contain no less cholesterol than those that haven't been fed a supplemented diet. Too bad.

Wednesday, April 17, 2013

I want me some sugar!

Species name: Saccharum officinarum

Common name: sugarcane

Location: Dominican Republic

Sugarcane is one of the most important crop species in Latin America. It is originally native to southeast Asia around Indonesia and Papua New Guinea, but has been transported all around the world and is widely grown in tropical countries. It is not only used to make sugar, but also as a food crop (black sugarcane can be eaten like a root vegetable), as a biofuel (in Brazil, sugarcane waste is burned for fuel and accounts for almost 80% of their power generation), and as a fermentable crop (to make rum).

White sugarcane is the primary crop species used for sugar production around the world (this isn't the case with sugar produced in northern climates; sugar in Canada and Europe is produced from sugar beets), and is chewed by children as a sweet treat. The canes are pressed either mechanically or physically using donkeys (rarely horses) to turn giant wheels of stone to press the juices into a big vat. The cane juice is boiled to condense the juices, and the molasses are filtered out from the rest of the cane juice. They can be added back in later in various amounts to make light or dark brown sugar, or left out to make white sugar. The filtered cane juice is heated to boil off the liquid and the purified sugar is left behind. Interestingly, this process was unlikely to have been "invented" in Latin America despite its widespread proliferation there. It is actually believed that the purification of sugar was first done in India.

Black sugarcane is very different from white sugarcane. It is not as sweet, and the centre of the stem isn't as woody. Superficially, it looks nearly identical to white sugarcane except for the colour of the stem. This variety of cane, however, is never used to produce sugar. Instead, the stem is peeled and cut into pieces and can be boiled and eaten like a very starchy, somewhat chewy and crunchy potato. It can be further sweetened (as ironic as it is to sweeten sugarcane) to be added into desserts. I've never tried black sugarcane, but people in Dominican eat it all the time as one of their traditional foods.

Sugarcane isn't just for making rum and sugar! Historically, sugarcane was a very important medicinal crop, and still is in Ayurveda in traditional Indian medicine. In fact, whenever you see the Latin epithet (the "second name" of a species) "officinarum," or a derivative of it, it means the plant was once used as a medicinal plant. In its medicinal use, young sugarcane stems are ground in a big mortar and pestle to produce a paste, and that paste can be applied on the skin to treat skin problems and to prevent infection. It might seem a little far fetched that this could be useful, but when you think about other very sugary products it actually makes complete sense. Honey, for example, doesn't need to be refrigerated (neither does maple syrup) because it is SO sugary. Very few organisms can grow in something that sugary not because it's so sweet, but because of the osmolarity of the substance. Osmolarity is a way of chemists and biochemists measuring how much water will move out of a cell; if a solution has high osmolarity it means that there is a high concentration of "stuff" (sugar, salt, another chemical, etc.) in the solution. Water always moves to equalize the solution with the cell, so water would move out of the cell and into solution (to try to get the ratio of molecules of solute to molecules of water to be the same). This means the cell will shrivel, and if too much water leaves the cell then it cannot survive. By drastically increasing the osmolarity on the surface of the skin, you make it a very hostile environment for pathogens to exist and so you may prevent infection. It can also draw water out of the skin and into the sugar creating a goopy mess; for this reason sugar is clearly not the favoured product to use for this purpose. This is the same idea that products like Polysporin operate on; if you read the ingredients label you'll see they contain a lot of salt to increase the osmolarity at the skin's surface, making it a hostile environment. Unfortunately, this is also the reason why your skin gets wrinkly and gross when you use too much of it too often. Skin needs the proper chemical balance, too!

Sugarcane can also be used to supplement animal feed; studies have shown that when piglets are fed sugarcane juice added with their regular soy diets grow faster and are susceptible to fewer pathogens than piglets fed a regular soy diet. Will sugary diets become the new norm in piglet feed? I doubt it. Pigs have the same reactions as humans to sugary diets. They get fat! This might not be a bad thing when you're raising piglets for their end product: consumption. If you want healthy pigs, weaning them off a high-sugar diet before they reach adulthood is very important; no one wants a fatty ham or a fatty tenderloin!

Monday, April 15, 2013

The nasty side of the Golden Trumpet

Species name: Allamanda cathartica

Common name: golden trumpet, yellow trumpet vine

Location: Dominican Republic

The golden trumpet vine is native to Brazil, but because of its pleasing aesthetics has been transported around the world to different tropical locations as an ornamental species. Unfortunately, in almost all of those locations it has become invasive not because of its seeds, but because it reproduces asexually so readily. This plant is usually used as a hedge and is pruned multiple times per year, causing the stems of the vine to be cut up. Normally this isn't a problem but for a plant like this that can root so easily from cuttings it's potentially disastrous. Each tiny piece of plant can become a new one, and so without proper disposal of all fragments the vine can very quickly get out of control.

One of the most impressive qualities of this plant is how quickly it grows. Unlike many other vines, it does not have its own support system so requires a trellis to prop it up off the ground (or it could be grown as a ground-creeping vine; it doesn't anchor itself in the ground like English Ivy does which you can read all about HERE). It also doesn't have tendrils or circular stem growth like peas do, so it also won't strangle plants it is propped up against (but will, more than likely, shade out any competitors). In only a couple of months during the peak of the growing season, it can grow up to 20 feet. Yes, twenty. That wasn't a typo. That's a few inches a could almost watch the plant growing if you could sit still long enough. That's insane.

Aside from the ridiculous speed of growth, this plant also has intoxicating yellow flowers. The flowers fully open just at sunrise, releasing a huge amount of scent along with them that you can smell from tens of feet away, in the attempt to attract their pollinators: hummingbirds. Hummingbirds are most active and looking for nectar first thing in the morning when they're still trying to recover from their overnight tropor or short hibernation. Warming such a tiny body up can only be accomplished by moving flight muscles, which hummingbirds can do at extraordinary speeds. This, as you can probably imagine, requires a whole lot of energy. Where does this energy come from? Sugar! And where does sugar come from for hummingbirds? Nectar! So the fact that these flowers open and are right ready to accept hummingbirds first thing in the morning means that the flowers are going to be visited right away if there are hummingbirds in the area. If this plant is propped up off the ground and allowed to grow in very dense clumps beside a wall for shelter, chances are you might find a hummingbird nest inside the clump of vines if you look hard enough. It would be like a Canadian Tim Horton's addict setting up a tent right outside a store. You can get your fix of morning java as soon as you wake up!

Unfortunately, this plant isn't just fun and games and pretty flowers to look at it. It is incredibly toxic, and the toxicity of the latex is enough to induce second-degree chemical burns if it stays on your skin long enough. If you are around this plant and are pruning it, PLEASE wear gloves and a long-sleeved shirt and pants (not to mention closed-toe shoes. Toes get ignored the most when it comes to gardening, and the last thing you want is a second-degree burn on your feet!). Also, there should never be a circumstance when you decide eating this plant would be a good idea. The toxic chemical called allamandin in the plant will cause severe vomiting, diarrhea, dehydration, liver failure, kidney failure, coma, and potentially lead to death. As with many toxic plants, this plant may have a redeeming quality or two: in very low doses, allamandin is sometimes marketed in "natural" laxatives because of its cathartic qualities. Also, pure extracts of the latex of the plant show that it has potent antimicrobial and anticancer properties, so it might one day be used in conjunction with current cancer treatments. Every thorn has its rose (or something like that).

Saturday, April 13, 2013

A miracle plant with a cure for everything?

Species name: Ixora coccinea

Common name: jungle geranium, flame of the woods

Location: Dominican Republic

The jungle geranium is an incredibly popular ornamental species in tropical locations because of how easily it's pruned into shapes. In tropical resorts, it's often the plant that makes up the "thou shalt not pass" barrier between the walkways around the resort and the grass and gardens beyond the walkways. It is native to India, Bangladesh and Sri Lanka where it is said to be one of their holy plants.

One of the best characteristics about this plant that makes it so ideal as an ornamental species and even a houseplant is that it can tolerate hard pruning and it flowers on old growth, the previous year's growth, and new growth. This is often a problem for some plants like hydrangeas and hibiscus, where they only flower from the previous year's growth and so if you prune this off in the spring or fall you don't end up getting any flowers. Many gardeners get around this by giving the plant a hard prune once every 5 years or so and just sacrificing the flowers for a year (it will still grow up with green leaves, but just none of the showy flowers). It also flowers almost continuously during the year, but just at different intensities; the most flowers appearing just prior to and just after the rainy season. As an indoor plant, this species is often grown as a cultivar with orange or yellow flowers, or even flowers that change colour as they age. I have seen these plants in garden stores here in Canada and always been amazed by the flower colour-changing ability but never been interested enough to try to keep one alive. Maybe I'll give it a shot next time I see one!

This plant isn't just loved for its ornamental value; it's also an important plant in traditional Indian mediciine called Ayurveda. The flowers, leaves, roots and stem are all used, often as a tonic or a tea, and consumed to treat a big list of ailments. The fruits of this plant are also edible but (from what I understand; I've never tried one or even seen one) don't taste very good. Biochemically, this plant has incredible amounts of chemicals that are believed to have some sort of health-improving effects: lupeol (anti-inflammatory), ursolic acid (used in the cosmetic industry but also inhibit cancer cell growth), oleanolic acid (antitumor and antiviral properties), sitosterol (a plant sterol that can reduce blood levels of cholesterol), rutin (blood thinner and anti-inflammatory), anthocyanins (anti-aging), kaempferol (analgesic), and quercetin (antiviral, anticancer, anti-inflammatory). While none of these chemicals have been shown to have these effects on large-scale human trials (most are at either the mouse testing or cell-line testing stage), so far all research has been shown to be promising. While this certainly is not an endorsement to go out and eat kilograms of this plant every day, perhaps Ayurveda is really onto something with this plant. We'll have to wait and see.

Monday, April 8, 2013

When a flower isn't a flower: part 2

Species name: Euphorbia pulcherrima

Common name: poinsettia

Location: Dominican Republic

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

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

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

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

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

Sunday, April 7, 2013

When a flower isn't a flower: part 1

Species name: Bougainvillea spectabilis

Common name: bougainvillea, Napoleon, veranera, trinitaria (amongst others)

Location: Dominican Republic

Bougainvilleas are some of the most well known and well recognized tropical plants in the world. They originated from a relatively small band of South America, extending from Brazil west to Peru and south to Chile and Argentina. Depending on who you ask, there are between 4 and 18 species in the group (18 species is probably an over-estimation due to morphological variation displayed even in a single group of individuals, but I doubt there are only four species since diversity of plants in the tropics is so high). DNA sequence analysis definitely needs to be performed on this group to help not only with defining diversity, but also establishing if any of these populations (however isolated) are their own species and hence are in dire need of protection and conservation. One of the reasons why this is such a popular "resort plant" in tropical countries is because of its extreme ability to tolerate salt (it can tolerate being watered with seawater! That's salty!) it makes for an ideal ornamental species where salt spray (and periodic flooding due to storm surges) is common.

The "flowers" of the bougainvillea plant are great examples of how plants can entice animals into believing that they produce these large, showy flowers, but in reality produce small, barely noticeable flowers and fruit. The pink "petals" that many people believe to be the flowers aren't at all; they're just modified leaves containing pink pigments instead of green ones that act to attract pollinators (we call these bracts). The flowers themselves are the small white bits on the inside; there are usually three white flowers surrounded by three to six bracts. The bracts can be white, yellow, orange, red, pink, purple, green, or any colour inbetween. The only colour of bougainvillea bract that I don't think exists is blue; feel free to correct me if you've ever seen a blue one! There are over 300 different varieties of bougainvillea sold as ornamental plants, so it wouldn't surprise me if it had been "invented". Not only have there been hundreds of cultivars and varieties created through selective breeding, but bougainvilleas also naturally hybridize in the wild. There is even a population of plants in Peru, once thought to be a distinct species, that is a hybrid of two commonly found species. What's unusual about this hybrid population isn't the fact that it's a population of hybrid plants, it's where the parental plants are located. And that's nowhere near this hybrid population. There's no documented evidence, either, that either of the parent plants of this hybrid ever existed in this area of Peru. So how did they get there? Is this evidence of "early gardening" by native Peruvians? Is this evidence for population reduction in both parental species of bougainvillea? Can the seeds really be carried that far? Is there an animal vector (or was there an animal vector) that eats the fruit to disperse the seeds that we don't know about? Some fascinating questions with (so far) no conclusive answers.

Other than the ornamental value, this plant has no other uses to humans. The sap of the plant to some people is highly irritating to the skin; in people who are highly sensitive to the sap the reaction can be as extreme as it is to poison ivy. Other people either don't react at all or react with a slight rash and a mild itching. Luckily, unlike with poison ivy, a cut portion of the stem must come in prolonged contact with the skin in order to cause a reaction. This means that you should only be worried if you have been given the task of pruning a patch of bougainvilleas; if you have, make sure you wear a long-sleeved shirt and gloves and you'll be fine. This is also a very popular plant to turn into a bonsai (although, a different species is often used; B. glabra). The bougainvillea is the national plant of Guam, as well as the regional flowers of regions in China, Japan, Taiwan, Malaysia, Philippines, and the United States.

Stay tuned for part 2 of "When a flower isn't a flower" tomorrow, featuring one of the most commonly purchased plants for ornamental, indoor use.

Saturday, April 6, 2013

This cactus doesn't just have roses. It also has leaves!

Species name: Pereskia bleo

Common name: rose cactus, leaf cactus

Location: Dominican Republic

This species of rose cactus (there are 17 species in the genus, all of which carry the common name "rose cactus") is native to the Caribbean basin, from Panama south to Colombia. It has been spread throughout Central America and the Caribbean Islands as an ornamental species, and it is now incredibly popular in gardens and as landscaping plants around hotels. I saw this plant at the farm we went to, and weren't given much information (if any; I was a straggler at the back of the group because of my compulsive picture-taking) about it. It's unfortunate; the people living there probably would know more about the plant than even Wikipedia does!

Surprisingly enough, this plant is a true cactus. You don't have to tell me it looks nothing like what you would picture to be a "cactus" because I most certainly agree with you. Unfortunately, we would both be wrong no matter how adamant we were about this not being a cactus; DNA sequence data tells us it is in the cactus family. Ah, well. Better luck next time to us! :) The genus can be split into two groups called clades, where each clade is a group of species that are most closely related to each other than they are to any other member of the other clade. Each clade has a very interesting characteristic that can be used to define members of that clade: geographic distribution. All members of clade A, where you find the species Pereskia bleo, are native to the land around the Caribbean Sea, from Mexico south to Venezuela (and also some species native to Hispaniola, the island that is made up of Haiti and the Dominican Republic, as well as Cuba, Jamaica, and the Dutch Antilles). Clade B, on the other hand, is made up of species native to South America near the Amazon basin in Brazil, Uruguay, Argentina, Bolivia, Paraguay, and Peru. The one exception to this rule is in clade B where we find the species P. aculeata which is native to a huge area from Mexico all the way south to Argentina. One thing that all of these species have in common is that they don't tolerate full sun very well; they much prefer to be found in shady areas. If exposed to full sun they will more than likely lose all their leaves and turn into a bush of sticks. This definitely won't kill the plant; the stems are green and they would be able to manufacture sugars using the energy of the sun quite easily (photosynthesis). They won't, however, flower or be anything fancy to look at. Best to plant it where it receives at least shading from a building or tree.

In Singapore, where it was introduced a few centuries ago, it is a very important medicinal plant in their traditional medicine, and the plant is called the "Seven Star Needle." The leaves are either chewed (if young) or brewed into a tea (if older) and consumed. It is believed that the regular consumption of these leaves will prevent cancer, but there is absolutely no scientific evidence to support these claims. I doubt the plant is toxic, as the people who make these claims would likely be dead from chronic poisoning if this were true, but don't start eating the leaves in an attempt to ward off cancer. The only evidence that this might one day be used to fight cancer is in mammalian cell lines; extracts from the leaves do kill cancer cells and prevent their proliferation. A word of caution before you get to excited: cell lines in culture behave very differently than what cells do in the body, so the fact that this has been demonstrated to be true has no weight with the medical community. Once (if) there is a long-term full-scale human trial with leaf extract, then the results might be meaningful to the human medical field.

Wednesday, April 3, 2013

Tropical Agriculture: Vegeculture

For this blog, I wanted to do something a little different. The way that agriculture "works" in different countries around the world is very different from what we, as North Americans, are used to. When I first found out that you could grow more than one crop in a field at the same time I was baffled. I had grown up driving up and down the 401/402/403 corridor where you see nothing but endless fields of corn (or wheat or soybean or whatever it is that the farmer is growing in the rotation that year). Or, if the farm had been subdivided into smaller plots, each plot would still be its own crop. I've even driven repeatedly by a sod farm and was amazed that people actually farm grass (but I guess sod does have to come from somewhere, doesn't it?!).

In warmer climates in Central and South America, as well as almost all of Asia, some of Australia and almost all of Africa, agriculture is very different. Instead of relying on one crop for a field, a whole bunch of crops are all planted at the same time in a small area. The idea is that if one crop fails, you still have other sources of food to rely on. Very few of these crops would interfere with each other, and some might even act synergistically to increase yield. A very exciting prospect, especially as we are struggling to produce enough food for the world's ever growing population. So how does this work? It's not just a haphazard mess of plants in a dense thicket and you get what you get. There is still a significant amount of order in a tropical food plantation, and there's a lot of planning that needs to go into making sure that taller plants that will grow into trees or large shrubs won't be planted near plants that cannot tolerate shade. Plants with vast root systems should be planted near the bottoms of trees that are already established so they can't compete for resources (the tree would almost always win that battle!). This type of agriculture is sometimes referred to as "vegeculture" (monoculture planting in cooler climates is called "seed planting" agriculture), and since I was lucky enough to be able to visit a small farm in Dominican Republic I figured it was worth exploring a bit.

I present to you...vegeculture!

These first two are photos of what a typical farm plantation might look like. You can see that there's still a semblance of rows that are planted, but the rows also each have more than one plant species. There is no effort put into weeding or spraying against weed volunteers (a "volunteer" is either a plant seed from the previous year's crop that pops up during the current growing season, or an adventitious weed that grows much faster than the crop you're trying to grow). Weeds are typically short-lived plants, and if you plant creeping vines as has been done in the upper photo then this is less of a problem (or is very quickly eliminated as a problem). So what do we have here? How many crops can you actually see in the photo? Well, when I was on the farm I counted at least 8 different crops in a very small space but now (of course...I didn't write them all down) I can only see six. So let's look at each one of these using the top photo, zooming in on some that can be distinguished easily (at the very least, picked out with the help of coloured boxes...).

Red box: This plant is very, very hard to see but it's certainly worth a short discussion. Between rows, cassava (Manhiot esculenta) is planted. Cassava, sometimes called yuca (NOT yucca!) or tapioca, is planted. The crop harvested from this plant are the very deep-growing storage roots that are used in a manner similar to a potato. The downside of cassavas is that they contain cyanogenic alkaloids (aka cyanide) and must be prepared very carefully. Once prepared properly, they can be sliced and fried or mashed and are often consumed in a stew-like preparation as a side dish for chicken.

Blue box: These are pineapples (Ananas comosus)! Immature pineapple plants just look like spiky plants you don't want to come across in a dark alley, eventually growing into the plant that can be easily recognized as a pineapple plant from my last blog post (which you can read HERE).

Yellow box: This is a low, creeping vine that is often propped up (either on stakes or in a more natural form as a corn stalk or sunflower stalk) off the ground. These are sweet potatoes (which might be called yams but are NOT true yams; Ipomoea batatas), grown for their sweet, potato-like fleshy root. Sweet potatoes, unfortunately, aren't always sweet. There are definitely the sweet sweet potatoes that we are used to in North America and that Europeans are used to, but there is also another variety (some call it species) that is much less sweet-tasting. There are also very lightly coloured sweet potatoes (not the bright orange-yellow sweet potatoes we're used to) which may or may not be correlated with sweetness (up for debate).

Pink box: This very tall, grass-like crop is sugarcane. There are actually two different types of sugarcane present, one called black sugarcane (the one that's outlined in the box with the black-purple stem) and regular sugarcane (the tall grass in the purple box; both the species Saccharum officinarum). Black sugarcane, while loaded with sugar, is not used to extract sugar from. Instead, in the Dominican Republic, it is used to cook some of their traditional foods and is eaten whole when young. The regular sugar cane is what is grown for sugar extraction.

Purple box: Bananas, relatively short-lived as far as "trees" go, are often planted as a staple crop in tropical countries. Sometimes these banana trees are true bananas (Musa acuminata x balbisiana; read all about bananas HERE), while the rest will be plantains (the same species, but a different hybrid cross). They are much starchier than dessert bananas, and are much more versatile in cooking. The dessert bananas, part of the ABB subgroup, mean that they have two times the number of Musa balbisiana chromosomes in their genome than plantains, which are in the AAB subgroup (twice the Musa acuminata genes). It seems as if the back-cross, what gives that second either B or A genotype, is what determines the sweetness versus the starchiness of a banana.

Brown box: This is a coconut palm tree (Cocos nucifera which you can read all about HERE). Interestingly, there are more coconut trees in the Dominican Republic than there are people and all of them are owned by the government. If you want to buy coconuts they are delivered by the thousand (yes, that's right. The smallest number of coconuts you can buy at a time if you are a Dominican citizen is 1,000 coconuts) in a truck, and you're set for quite a while. Coconuts are one of the most versatile foods in tropical countries because they're not just used for food! If you carefully cut out the flesh you can use the leftover hull as a drinking vessel, the juice on the inside (the coconut water) can be used instead of saline solution in hospitals or cooked with, the flesh can be turned into coco butter or coconut oil for cooking (or eaten cooked or raw), and the hulls can be burned for fuel. The hulls also contain very strong fibres that can be woven into mats or cordage. You can see why they're so popular! The wood of the tree can also be used as either firewood or as a building material, depending on the age of the tree (the older the tree the less structurally sound it is, and the less likely it can be used, or would be used, to build a house).

This is just a small sampling of the number of species this one farm was growing; they also had breadfruit, mango, papaya, cotton, peppers, sage, basil, coriander/cilantro, thyme, allspice, coffee, cacao, tamarind, and annatto (to name a few...)! A pretty productive farm, and nowhere near the size of a multi-crop fruit and vegetable farm in Canada or the United States!

Unfortunately, more and more "traditional" cropping systems are popping up in Central and South America, due mostly to the influence of North American principles on traditional practices of South Americans. Sugarcane, banana and tobacco plantations are becoming more and more prominent, and are leading to serious problems with crop losses because of multi-chemical resistant pathogens that are attacking the fields. This is also leading to increased spraying, and since there aren't as strict regulations in these areas with chemicals that can and cannot be used on edible food this is being passed down to consumers in countries that import these crops. Many of these chemicals are highly carcinogenic, meaning they can cause cancer in very small quantities. Others are highly allergenic, and may explain at least part of the reason why some children are developing multiple food allergies. For example, there is a very high prevalence now of children being diagnosed as being allergic (or "intolerant") to gluten. Strangely enough, these same kids have no problem if they're eating homemade bread. It's just the bread in the bag from the mass-producer that causes them problems. Obviously this isn't a case of gluten intolerance; gluten is in all wheats, regardless of where it is acquired or how it is processed or who bakes the bread. The difference is in the number of chemicals on the wheat itself: if you bake your own bread you have the choice of where you obtain your wheat flour and if it's "organic" (however the farm or governing body defines that word) or not. A very interesting theory, and time will tell if there's any weight behind the idea!

Monday, April 1, 2013

Pineapples don't grow on trees!

Today, being April 1st and all, I was going to photoshop two plants together and then "publish" a new species on my blog. Come up with a really creative name, pretend it has some ridiculous medicinal quality that I discovered while experimenting on my cat, and describe its ability to not only transport itself from one place to another by its roots, moving through sandy soil, but also that when the flowers open it moos like a cow. Yeah, big plans. But then you know what? I remembered I didn't have a clue how to use photoshop properly. Maybe I'll learn in time for next year's April Fools :)

Until then, 365 days from now, you can enjoy a (100% true) blog about...pineapples!

Species name: Ananas comosus

Common name: pineapple

Location: Dominican Republic

Pineapples. What to say about pinapples?! Well, the first thing to mention is that they do not grow on trees (you can read all about pineapple-like trees HERE). Pineapples are monocots; they don't have the ability to form wood and so cannot be a tree. Plus, from the first picture you should be able to see that they're more like a shrubby, spiky, rather dangerous-looking plant. This observation would be completely true; some of the people that were on the safari excursion with my mom and myself came away from the "farm tour" with scratches all over their legs from brushing up against pineapple plants. The leaves have razor-sharp spines all along both sides and they can slice through skin with the very lightest of pressure. Definitely a plant to stay away from unless you're wearing pants!

Pineapple plants are native to South America, at least that is the current school of thought. Very little is known about the actual domestication of pineapples, nor what the likely ancestor of a domesticated pineapple actually looks like. What is known is that the domesticated pineapple was introduced to the Philippines and to Hawaii very early on, likely before the days of Marco Polo and the Dark Ages. It seems as if no one could quite figure out how to propagate them, and they were eliminated from the agricultural crops of these locations until their re-introduction. It is said that pineapples were re-introduced in the 1500s to Hawaii by the Spanish, but this is widely disputed. We do know that they were cultivated there by 1720 in "pineapple pits", and a widespread re-introduction in the early 1800s caused them to be (and still are) one of Hawaii's most important export crops beginning in the late 1800s. In the Philippines, it is believed they were introduced sometime in the early 1800s, probably by the same Spanish ship that introduced them to Hawaii, and they have become a staple in rural Filipino life. The leaves contain very strong fibres with a very unusual texture (almost like silk when you run your hand along a garment in one direction and feeling like burlap in the other), and this has been used to make traditional clothing for at least two centuries. Now, pineapples are cultivated in the Philippines (mostly just exported to other areas in Asia and in Australia/New Zealand), Costa Rica (where Del Monte produces all of its pineapples after the breakup of the Pineapple Research Institute in Hawaii), the United States (where Dole still grows a lot of its pineapples), Thailand, and Indonesia.

Pineapples carry a lot of controversy, especially with the methods used to cultivate them. Pineapples are all clones of each other; that's the only way you can ensure the fruit obtained will be the same sweet, juicy pineapple consumers have come to love and expect when they buy pineapples. Unfortunately, whenever you clone a plant you make it unable to evolve resistance to pathogens, and pineapples today are attacked on a daily basis by fungi, bacteria and viruses that have evolved virulence genes against the plants. In order to fight disease, this means pineapple plantations must be sprayed, sometimes upwards of 40 times over the time of fruit development (which is only 6 months), just to prevent disease. The chemicals sprayed on pineapple plantations are incredibly dangerous to the health of the workers on the plantations: every chemical sprayed is carcinogenic, many are organophosphates which destroy the environment and can affect brain development in fetuses, and some are hormone disruptors which can have adverse effects on child development (they have been linked to everything from autism to attention deficit disorder to spontaneous miscarriage, brain cancer and leukemia). These chemicals aren't just dangerous for the health of the workers that spray the fields and work in the fields all day; these chemicals are leached into the drinking water supply and are consumed downstream by everyone in surrounding villages. This is a real problem, and there have been many lawsuits filed against both Dole and Del Monte along with encouragement to solve this problem by working harder to develop different cultivars that are disease resistant. There is some effort underway in pineapple biotechnology, but because of the "bad rap" that genetically modified food has, none of these products have made it to widespread cultivation. Remember, too, that if a chemical is sprayed onto the surface of a food item, it is more than likely incorporated in some way (however large or small) into the food that is consumed. Some food for thought (pun intended).

Pineapple fruit develops in a very unusual way; a way that is not shared with any other fruit commonly consumed worldwide. It is called a "multiple" fruit, because it is a single fruit made from multiple flowers. The entire inflorescence of the pineapple goes into making a single fruit! Each flower must be pollinated, usually by bees or hummingbirds, and then all at the same time the flowers mature into the pineapple. The actual pollination process can take from 20 to 24 months! That's two years just to get the beginning of a pineapple fruit. That gives me a whole new appreciation for my pineapple. After all of the flowers have been pollinated, the fruit takes another six months to become fully mature. In the third picture, you can see some of the flowers emerging from the inflorescence. Unfortunately, this entire process is actually detrimental to pineapple production since flower pollination implies seed production. No one wants to be eating seeds in their pineapple! For this reason, pollinators of the pineapple plants have been banned from import by the Hawaiian islands, to prevent unwanted seed development. If no pollination occurs, the fruit still develops but just no seeds are formed. The pineapple is said to be a "mathematical" fruit; the flowers are arranged in two spirals around the inflorescence stalk, with one spiral going each direction. If you count the number of flowers in a spiral one direction it's 8, and the other is 13. This means that the pineapple is an example of a fruit in nature that displays the Fibonacci number sequence. Neat!