Burr it's cold!

Species name: Arctium sp. (probably Arctium lappa)

Common name: burdock (probably greater burdock)

Location: Western University Campus, London, Ontario

I decided to start this year off with a bang, or a burr if you will, using a blog post with lots of pretty pictures. :) Who doesn't love pretty pictures?! The burdock plant is pretty well-known in North America where it was introduced from Europe, the Middle East and Asia (pretty much every area in the Northern Hemisphere EXCEPT North America). Across its native and introduced range it has the potential to become quite invasive, as it thrives in disturbed, nitrogen-rich soils. This makes it an especially-potent agricultural weed species. In most cases, however, when burdock seeds enter an area (especially a landscaped garden like you'd find around a home) a couple might develop into plants but spreading is rare. While I took these pictures on campus, there is also a very small colony (two plants) growing in my back yard. Since they're out of the way, I've left them there and hoped that the "keeper of the garden" (aka my dad) doesn't find them ugly enough to remove. To me, they're pretty in their own way. I wouldn't want lots of them (since they're irritating in their own way, too!), but one or two is just fine.

I had a bit of trouble getting this plant down to the species level because I neglected to make notes of (or take pictures of) the distinguishing characteristics between the greater burdock and the lesser burdock. One of the main ways to tell them apart is by looking at the base of the flower, or what we would call the "burr." If the flower is on a stalk, it's the greater burdock, and if the flower is directly attached to the branch (or is on a very short stalk), it's the lesser burdock. Since I think these pictures are just great, I'm going to go with the greater burdock :) Next time since I know what I'm looking for I'll make sure I photograph the stalks (or lack thereof) that the flowers are sitting on so I can make sure my identification is correct! There is one more burdock species in Ontario (also a non-native species) called the woolly burdock, but this one is easily distinguished from the other two. It has a bract at the bottom of each leaf that has very fine spike-like hairs on it. Neither of the other two species we have here show this characteristic. Aside from the flowers on (or not on) stalks, the other way to tell the lesser and greater burdock apart is based on size; the greater burdock is almost twice the size at maturity, and can have a taproot up to three feet long. For a plant that's only about three times bigger than that (but many in Canada don't reach that size), that's an enormous root! For all three species there are separate male and female flowers within the flower head. You can tell the difference by looking for the stigmas (the female bits of the flowers); they are pointed out with the bright pink arrow in the picture third from the bottom. Usually the stigmas only develop after the stamens of the male flowers have released their pollen; this way the plant can make sure the stigmas will catch pollen, but it won't be its own pollen; this is one of the mechanisms most often used to ensure cross-pollination between individual plants, rather than the pollen of an inflorescence landing on the stigma from that same inflorescence.

The burdock plant is pretty awesome for two reasons. First, if you look closely at the last picture you'll see that the burrs open up at the top to release the seeds, which are like miniature dandelion seeds, fluffy bit and all. The actual burr is covered in hairs with a hook at the end, and the tip of the hook has a very sharp point. This makes the burr feel "sticky" when you put it on your skin or when you grab at one, even though there's actually no sticky substance on the hairs. If you own a dog and have ever walked it through a forest or a field, I'm sure you're well aware of the nightmare that is "de-burring" a dog. The type of hair that covers dogs is just made for burrs using those hooked hairs to latch on for seed dispersal. Eventually, the dog will roll around on the ground, breaking open the burr and releasing the seeds (or the seeds will just gradually fall out of the hole in the burr, being released as the dog walks). Burrs certainly didn't co-evolve with dogs, but more like woolly mammoths, bears, moose, and other animals characteristic of northern climates (dogs just happen to be what is most likely to come by now). In the 1940s, a very smart man by the name of George de Mestral was getting very annoyed at having to pick burrs off of his dog after taking him for walks. After a few years of this he decided to clip some out of the dog fur instead of pulling them off so he could look at how the burrs attach to the dog hair. He realized he could exploit this technology; by collecting his dog's hair that comes off in brushes and the hairs of the burr, he could glue one to one side of two things he wanted to join, and glue the other to the other side. Once they come in contact, they would be permanently joined until they were carefully separated. Obviously no one wants dog hair and burrdock burrs glued to their clothing, but making synthetic versions of both of these gave us one of the most important inventions in the 20th century: velcro. Parents will small children: Mr. de Mestral I'm sure says "you're welcome!"

The other awesome part about this plant is that the giant taproot forming at the base of the plant is actually edible. Back in the Middle Ages in Europe this plant was actually one of many staple food crops, and was eaten and cultivated across Europe. Since then it has largely been abandoned as a source of food, but every so often you find it popping up in local cuisine. In Japan, for example, greater burdock roots are still peeled and cooked in a traditional stir-fry dish called kinpira gobo ("kinpira" for carrot, "gobo" for burdock). I didn't realize what I was eating at the time, but I had this dish when I was in Japan. It's pretty good! Not all that much flavour, but certainly not undesirable. I would definitely have it again now that I know what I'm eating.

Greater burdock roots also have a long history of being used in Traditional Chinese Medicine to treat blood and kidney diseases. Depending on what part of the plant is consumed (not the roots), it can be a pretty powerful diuretic, so if you don't know what you're doing, don't cook it. Other medicinal uses have not been established to be effective or ineffective, but there is some anecdotal evidence to suggest that some uses may be beneficial. First, the Ojibwa people have used burdock roots in a tea-like preparation to treat cancer (no evidence this is effective) and the leaves in a maceration with oils to treat baldness (also no evidence this is effective, but it does clean hair nicely if rinsed well). The Chinese also crush the seeds and consume the powder to treat flu, nausea and colds, and there is some evidence that this might be effective. The seeds contain chemicals called arctigenin, arctiin and aglycone, which have been shown in mice to be effective as: anti-viral treatments (especially against influenza A), anti-inflammatory agents (especially in the small intestine, but also to some degree in swollen joints as a result of arthritis), and anti-cancer treatments (extracts from the seeds, and pulverized seeds themselves, have been shown to kill tumour cells growing on artificial nutrient medium in petri dishes; this has never been tested in a living body of any type of animal). You never know; in a few decades burdock extract might be one of our new "wonder drugs"!

I'm back at blogging, and thanks for sticking through my absence! I really appreciate all of your continued support in my endeavours to spread the word that plants are awesome. Happy New Year to those that celebrate at this time of year!

BLOG RERUN: Happy Diwali!

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

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

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

Common name: marigold

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

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

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

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

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

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

Las Tres Hermanas

Today instead of a "regular" blog where I only profile one species, I figured I would profile a mini-ecosystem, and a traditional method of growing crop species. On campus there was a recent initiative to convert some "wasted space" (a plot of land completely over-run by Japanese knotweed, which you can read about HERE, and buckthorn, which you can read about HERE) into a garden. This isn't your everyday garden, even though at first glance you might think it is. This is an Aboriginal garden. What makes that different from a regular garden? Well, all of the plants grown in the garden have traditional uses, and some are even heirloom varieties, to Aboriginal North Americans. Many of the species grown are food crops, and they're grown in the same manner that their ancestors would have grown them, and they're growing the same varieties that their ancestors would have grown 3,000 years ago. I find this a pretty mind-boggling idea: growing the exact same genetic variety of plants as your ancestors did 3,000 years ago. Not looking up at a 3,000 year old tree and thinking "gee, I wonder how it got here" (there are very few of these left in the world, but they do exist), but growing the same food to eat that your ancestors ate. Awesome! There are a bunch of other plants in this garden other than just the three I'm profiling (including "medicinal tobacco," which is a concept I will never understand) so if you're on campus sometime next summer or fall make sure you walk around the outside of the garden and check out what they're growing (the garden is behind Collip building, near the lower greenhouses. A PDF map of campus is available HERE).

So with out further rambling, I present the Three Sisters:

Sisters, huh? These are three crop species all domesticated at about the same time (5,000 years ago) all in the same place (Mexico), and all eaten at the same time. Corn, squash and beans all contain different quantities of essential nutrients, and when the three are eaten in combination they provide an excellent balanced diet. Corn is rich in starch, beans are rich in protein, and squash contains many of the vitamins and other nutrients not in the other two (plus has a nice sweetness to balance a meal). Sometimes you'll also find potatoes added to a Three Sisters soup, but don't worry. That should actually be called a Four Sisters soup, and would have been a traditional food of Peruvian people (once corn had been domesticated into a crop species and the knowledge and seeds were shared; potatoes, beans, and a different type of squash had all been domesticated in and around Peru about 9,000 years ago!)

So let's talk about each species!

Species name: Zea mays

Common name: corn

Location: Western University campus (Aboriginal garden)

First we've got the plant that's most easily distinguished in the first image, and that's corn. Corn is a very unique plant in that it is monoecious: this means it has separate male and female flowers on the same plant. The male flowers, called staminate flowers, are at the top and are often called the "tassel." The female flowers, called ovulate flowers, can be found at the base of each of the leaves and they turn into the cobs of corn that we eat for dinner. If you are driving down a highway in "corn country" (there are a lot of farms that grow corn in Southwestern Ontario, but also a huge number of farms in the southern United States), keep your eyes peeled for corn growing in tightly packed rows with signs at the end. There would maybe be 2 or 3 of these rows, then a large space (large enough for someone to comfortably walk down and be able to take notes or photographs), and then more tightly packed rows with a different sign. This is the type of growth and the type of planting that comes with field trials of experimental varieties of corn. If the varieties don't work (don't produce enough corn, the kernels are often misshapen, are more prone to disease, don't mature fast enough, or any other number of reasons), then they are scrapped and not grown again. Farmers can "lease" part of their land to plant breeding companies for field trials, and they are compensated often by square foot; for every square foot they allow companies to grow corn, they are compensated for the amount of money they would have earned by growing their own corn on that plot. So if market value of corn is very low, there's little incentive to lease out your land for experiments. If market value of corn is very high, you could lease out a small area, not have to water or fertilize it (so lower cost for the farmer), and still get the same amount of money out of it. Good deal!

But obviously all of this is an aside; I want to talk about corn, not about farming. What do experimental rows of corn have to do with the biology of a corn plant? If you look carefully at these rows, you might notice something missing. It's difficult to put your finger on it if you don't know what you're looking for, but look at the tops of the plants. Do you see any tassels? The answer is more than likely you don't see any. This is an ancient practice dating back to the very first attempts at domesticating corn. People figured out very early that in order to select traits you want to propagate, you have to know who the "parents" are of the plant. Male flowers blow their pollen everywhere, and if the pollen lands on the silks of a female flower then that pollen fertilizes that flower (each kernel of corn used to be its own flower, so in order to get a fully developed cob you have to have every single flower fertilized or you get those awkward holes in the cob that no one likes, and misshapen kernels around the hole). Not knowing what pollen landed on the silks is a big problem, so if you cut the tassels off the top then you eliminate the issue of not knowing what pollen fertilized the female corn flowers. De-tasseling is a very labor-intensive process, and is rarely done anymore with corn unless a breeding program is in place. There are other, much easier ways to sterilize corn but they all involve transgenic (genetically modified) plants. If you want to see how a new variety of plant is doing, usually it's not a transgenic plant (there are many, many regulations in place for new transgenic plants and testing phases; a biotechnology company can't just walk up to a farmer and say "hey! Grow this. I'll pay you.").

So what's special about corn? Well, we've managed to modify the plant beyond its biological means. What do I mean by that? Traditional breeding (controlled crosses of plants in attempts to propagate desirable traits; something still very common in the gardening industry with food and ornamental plants) has managed to completely eliminate the possibility of the corn plant being able to reproduce on its own. Think about the seeds: each kernel of corn is an individual seed, meant to be dispersed into the environment. How on earth is a corn kernel going to be dispersed when it's covered with all of those layers of thick husk? The husk does a great job of protecting the kernels from the outside environment (which makes a good cob to eat), but that's lousy for the plant. In fact, even if the thick husk didn't exist at all, the kernels now more often rot on the plant than fall off because of other traits we have bred into corn plants (no one wants all of their corn kernels loose in the husk, so our ancestors selected traits that kept the kernels on the cob for eating). There are so many modifications that have been made to corn that it now looks nothing like its ancestor, Teosinte. Teosinte is still relatively common in the wild, and grows like a weed. Corn? It would cease to exist in a very, very short time without human intervention.

Species name: Phaseolus vulgaris

Common name: common bean

Location: Western University campus (Aboriginal garden)

Common beans have themselves been domesticated separately dozens of times by different populations of people in Central and South America to create all of the different types of beans we have today. String beans, French beans, haricots, garden beans, navy beans, kidney beans, wax beans, bush beans, pole beans, black turtle beans, pinto beans, and pop beans are all different names of the same species, often associated with specific varieties of the plant (and there are many, MANY other types of beans that are all part of this species). I have no idea what variety or cultivar of beans these are, but they are the "pole bean" type in that they are climbing vines. When the Three Sisters are grown together, corn acts like the pole that beans can grow up. They in turn fix nitrogen from the atmosphere into a type of nitrogen that plants can use, which is like free fertilizer. The corn plant says "thank you very much" and uses almost all of it in order to produce the corn kernels. The bean vines are a bit hard to see unless you know what you're looking for, so I put a red box around where most of the bean plants can be seen. Look for a vine-like plant with leaves that each have three leaflets. It might look a bit like poison ivy has taken over the vegetable patch :)

Also highlighted in this picture is one of the neat characteristics about this traditional corn variety grown: when mature, the husks around the cobs turn a dark purple. In fact, if you compare the picture above (the husk is in the purple box) to the second picture of the corn plants, you can see the drastic difference in shade of purple that the husks are of those two corn cobs. A pretty neat indicator to know when your corn is ready to eat!

Species name: Cucurbita sp. (probably C. maxima)

Common name: squash

Location: Western University campus (Aboriginal garden)

The last of the three sisters is simply known as "squash", and could be any number of species or varieties. This type sure looks like a pumpkin to me, but it might just be a type of "Candy Roaster" squash which was actually domesticated in North America (in the southern United States by the Cherokee). The role that squash plays in an agricultural sense is a "Jack of all trades." The leaf stems or petioles are incredibly prickly with stiff hairs, which is a strong deterrent of agricultural pests. The leaves themselves are enormous, which provides a great amount of shade at soil level. This does two things: first, it creates a cooler microclimate at the base of the corn stalks so that the hot soil in the heat of summer doesn't burn the stalk, and second it shades out any weeds that might want to grow in the garden so the corn and beans can use all the soil's nutrients.

The nutritional side of the squash is two-fold. First, it contains a huge number of nutrients that the other two crops don't have but are necessary for proper nutrition like vitamin A, many of the vitamin B complexes, and vitamin C. It also contains quite a bit of sugar compared to starch, so can be used to sweeten a meal and impart flavour (corn and beans on their own don't taste like much, it's the liquid you cook them in or the spices you add that make them taste good). The seeds of squashes are also incredibly nutritious, but can also be pressed instead of eaten and used as cooking oils. If dried properly, the seeds can also be ground into a paste (the North American version of hummus?), or into a fine powder and used to make bread. Now that I know this I'm on the hunt for squash-bread. If you know how to make this, please let me know. It sounds delicious!

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So there we have it! The three sisters, all being grown just outside my building in a neat, new garden on campus. Now I'm tempted to make some corn, bean and squash soup for dinner...

You put your left flower in, you take your left flower out...

Species name: Physostegia virginiana

Common name: obedient plant

Location: Western University campus

I didn't realize until after I had taken and water-marked these photos that I had already blogged about this plant once. If you'd like to go back and read the first version, you can do so HERE. If you'd like to read a "better than the last" version, keep reading! :)

The obedient plant is one cool plant. Endless hours of entertainment if you're lost in a prairie (more on that later). The native range of this tiny plant is quite impressive, ranging from the northernmost edge of the temperate forest in Canada all the way south to parts of the (very small bit that's remaining) tropical forests of Mexico. If grown in Canada it illustrates the reason why I should have made the species status diagrams with a "common, native, invasive species" combination because it spreads very quickly and can dominate a landscape in just a few years. Where there is snow during the winter the plant will die off, but because of the extensive underground network of rhizomes it will pop back up in the spring and produce more of the beautiful flowers. If you're thinking of planting this species in your garden, then go ahead and do so if you live in my area. It's a native species, and it's never a bad idea to plant a native species! You might want to reconsider, however, if you have an intense aversion to weeding (it will spread, trust me) or if your yard backs onto an Environmentally Significant Area. For those locations, even the slightest change in dominant species (such as providing a source for a seed bank of a weedy, although native, species) could spell disaster for the area. Always make sure you keep in mind what is around you before making major changes to the landscaping in your yard.

This species is one of the best examples of a member of the mint family, or the Lamiaceae. The stems of this family are almost always square, while nearly all other plant stems (the notable exception are the sedges) are round in cross-section. You can see the ridges of the square stems of this plant clearly in the third picture, above. The leaves are also characteristic of the mint family: they are simple leaves with teeth (some members of the mint family have leaves with smooth edges) that emerge from the stem directly across from each other. The next node up (or down) on the stem will also have opposite leaves but they will be at right angles to the previous level of leaves. You can also see what I mean by this in the third photo. The flowers are also very characteristic of the mint family, although different varieties of this plant have been modified in different ways (sometimes quite drastically) to be different than the so-called "wild type." A wild type plant is a plant that would be found growing in the wild without having experienced any intervention by horticulturalists (or, in the case of edible plants, farmers). The group of plants above are pretty characteristic of the wild type of this species: purple-pink flowers, the flower petals are joined at the bottom and form a structure that looks like two lips at the edge of the flower, darker purple or purple-pink splotches on the bottom lip, and the sexual parts (most noticeable being the stigmas) being attached to the top lip of the flower. This "two lip" morphology isn't done just by chance by the plant; it's actually a flower shape that has co-eveolved with the choice pollinator of this species: bees. Something that you may or may not be aware about bees is that they can't see colours like we see colours. Everything green looks a very dark blue to them, so picking out flowers from a sea of blue-black is difficult, especially when you can't see them. Bess are special, though, because they can see a wavelength of light that we can't see: ultraviolet light. This means that anything that's purple, or even purple-pink, will glow when a bee looks at it. The flowers themselves aren't quite purple, so merely act as lightly glowing beacons in the sea of blue-black plant material. This is enough to entice the bees over, but the dark purple patches on the lower lips of the flower is what really brings the bees over. The bees see the structure of the flower, and use the lower lip of the flower like a landing pad (those darker splotches would be like the landing lights that pilots use to land planes on runways at night). The bee would wiggle around, trying to get its head as deep into the flower tube as possible to access all of the yummy nectar. This would cause the bee's back to rub up against the stigmas of the flower (located on the top lip, which you can see in the fourth and fifth pictures above), which would dust pollen all over the bee's back. Once the nectar is gone, the bee would fly to the next flower, do the same thing, and transfer all of the pollen from its back onto the stigmas of the next flower, ensuring successful cross-pollination. Sneaky little flower! But also quite a smart little flower.

So why is this plant called the "obedient" plant? Well...it stays where you put it. Huh? The flowers actually have the ability to swivel around the flower stalk, and when the flowers swivel into a new position they stay that way. Check it out below:

In the top photo all of the flowers are pointing towards the ground, which is actually pretty common in this species once the flower heads flop over (often they grow too quickly for their own stems to support them if conditions are ideal). In the bottom photo I took two of the flowers by the base and swivelled them around to point straight up. They'll stay that way for up to a minute, then flop back to their original position. If you give the flowers a break, you can move them back and forth multiple times before the plant will just give up on those flowers and dissolve them off the flower stalk. Only the best are allowed to set seed!

Will this plant really repel mosquitos?

Species name: Cymbopogon citratus

Common name: lemon grass

Location: teaching lab at Western

Lemon grass (or lemongrass. Same thing) is native to southeast Asia, which should be intuitive for those that cook international cuisine (or local cuisine, I guess, if you're in Thailand or the Philippines!) since it is heavily used in Thai and Filipino dishes. If you've never seen the full plant before (as opposed to just the bulbous bottom of the stalk in the grocery store like in the third photo), you'll notice it looks a whole lot like ornamental grasses you might grow in your garden if you live in temperate North America, like zebra grass (which you can read all about HERE). This species of plant, while not in the same genus as zebra grass, is a close relative and in the grass family.

Like ginger (profiled a few days ago in a blog entry that you can read HERE), lemon grass has a ligule that is useful in identification of the species. It is a very unusual ligule in that there are long hair-like appendages that protrude out of the base of the blade of each leaf, and the papery part of the ligule is short and has nearly a straight edge (which is unusual for a ligule; usually they're longer in the middle than they are on either side and somewhat semi-circular shaped). It's a pretty characteristic ligule, and I'm ashamed to say I didn't get a great picture of it when I had the chance. I'll have to go track down this plant in the greenhouse and make sure I get a good picture of it! Like other grass plants, but unlike ginger, lemon grass has very non-descript flowers that are pollinated by the wind (and that is actually a photo of the flowers in the fourth photograph). This is a characteristic of nearly all species in the grass family, where the amount of resources necessary to allocate to a "pretty" flower used to attract insects or small animals (like hummingbirds or even mice) is far more than it is just to give way to the wind and rely on having your pollen blown from plant to plant. This is partly attributed to the habitat in which most grasses live; wind is abundant in prairie habitats and cheap to use. If you rely on living pollinators to cross-pollinate your flowers, you may run the risk one day of having pollen ready before there are pollinators around to transport it for you. Grasses have evolved "simplified" flowers to eliminate this risk and maximize the potential for pollination. Smart grasses!

As well as the great citrusy flavour lemon grass imparts on food and beverages, lemon grass has been used in folk medicine around the world for centuries. In Brazil it is believed to by an anxiolytic and hypnotic plant, but anyone who has ever had Thai food or lemon grass tea could probably speak to the lack of both of these effects, even when the plant is consumed in large quantities or consumed in a more concentrated form like chewing the stem. In fact, no scientific studies have ever substantiated this claim. Lab studies, however, have shown that this plant has the potential to show some medicinal value. It does show cytoprotective and antioxidant properties, suggesting that this may somehow one day play a role in cancer prevention (no known method of exploiting antioxidants to either prevent aging or prevent the development of age-related cancers currently exists, no matter what anyone tells you). One of the chemicals in the extracted essential oils of lemon grass has been suggested to play a role as an antihypertensive, and in lab studies the pure form, called citronellol, has been shown to lower blood pressure in mice and rats so there is definitely the potential to use this chemical as a potential blood pressure herbal medicine. There have been very few reports of this plant being toxic to any kind of domestic animal (human or non-human pets), so you don't have to worry much if you grow your own lemon grass. Cats anyway will stay away from it because it smells like citrus; unless you've got an atypical cat, cats hate any kind of citrus. Lemon grass oil has been reported to cause mild skin rashes in people with sensitive skin, so if you have extremely sensitive skin be careful handling the fresh-cut plant.

Sometimes extracts from this plant are referred to by the commercial name "citronella," which many of you will recognize as an insect repellant. So does it work? In my experience, no. There is no amount of citronella that you can burn or put on your skin that will truly deter the bugs you are determined to deter: mosquitos (and sometimes deer flies and horse flies). You can never truly "deter" a mosquito. They are out for blood (literally), and "smell" you via the carbon dioxide in concentrated forms that you exhale (which you can't prevent yourself from doing) and by the chemicals you exude in your sweat. Deet is the only chemical that can truly make you "invisible" to mosquitos by camouflaging your scent and throwing off the mosquito's radar. Deet does wear off incredibly quickly, so if you're in an area with a high density of mosquitos you can essentially be guaranteed to be bitten anyway (especially if it's hot and you're sweating, effectively both increasing your hormonal signal to the mosquitos and washing off the deet at the same time). Some people are naturally more alluring to mosquitos because they give off more of the mosquito signal chemical, and so they require more deet more often (I am, unfortunately, one of those people...). By rubbing citronella all over yourself, you're just making yourself smell more like lemons than you are like a human. This can work for about 30 seconds to deter mosquitos, but it is not going to work in the long term. Sorry for ruining your day if you use citronella oil as a bug repellant and have been wondering why you still get bit all this time :)

Does this mean citronella NEVER works against deterring bugs? No, it doesn't mean that. Remember that essential oils produced by plants are secondary compounds usually used in plant defence? Well, it smells like lemons for a reason. Citronella IS actually an effective insect repellant; clinical studies have shown that it is nearly 100% effective in deterring fruit flies from a specific area where it is applied, and it doesn't have to be applied in large quantities. It also does a pretty effective job of deterring stable flies, which bite not only humans but also horses and cows if they get a chance (and these bites are incredibly painful, bloody, and result in enormous welts on the skin). Citronella oil definitely does have a good use in insect deterrence, just don't expect it to do anything for mosquitos!

A fibre-filled way to start your day: Eid Mubarak!

Species name: Phoenix dactylifera

Common name: date palm

Location: first 5 images from Dave's Garden user palmbob, last image from Dave's Garden user QCHammy

Date palms are magnificent trees (although, they're not truly trees because they're monocots and can't produce true wood), and not just because of their genus name (seriously? How cool is the genus Phoenix?!). And to be named after a dinosaur (the pterodactyl)? Awesome! OK, so I don't actually know for sure the date palm was named after a giant mythological bird that can be reborn multiple times and a flying dinosaur, but a girl can dream. The date palm was likely first domesticated to be an edible palm species in Iraq (most palm fruit you do not want to eat; many produce pretty potent fruit that would make you very sick very quickly), although a closely-related species was also domesticated in and around Brazil. They are now becoming very popular ornamental species in tropical locations because of a few ideal characteristics: they are long-lived, they are drought tolerant, are highly wind tolerant, and are tolerant of salt spray on their trunks and leaves (even when young).

Dates have been eaten as fruit for thousands of years. There's even evidence of date fruit being left as an offering in ancient Egyptian burial sites and in mummy sarcophaguses (sarcophagi? You get what I mean). No one is quite sure what the symbolism of leaving such fruit represents, as date pits are present with some bodies but not others. There is the suggestion that it might have to do with the time of year the body was buried (more on this later). Date palms are dioecious, meaning they have completely separate male and female plants. In order to have a date palm plantation, one must plant both male and female trees in order to get a crop (the male tree only provides the pollen, the female tree is where the fruit are produced). Unfortunately, the male plants are simply a waste of space in the plantation and so are usually not planted (sorry to all the men out there!), and instead alternate pollination methods are used. In certain areas, date palms are such important crop species that male flowers complete with pollen are often sold in jars in outdoor markets around the time that pollination would be occurring. If you were a date palm farmer, you would buy a jar and sprinkle the pollen in front of a large fan that would blow it across your plantation. I'm sure seeing this in person would be absolutely wild; not to mention it would really wreak havoc on your seasonal allergies if you had them! There are other ways to hand-pollinate female date palm flowers; in Iraq there are highly trained pollination personnel that climb the trunks using only a rope and pollinate the flowers using either a hand-fan or paint brush.

The fruits of these trees are remarkably nutritious, and are one of the best sources of potassium of any edible plant. They also contain a surprisingly high amount of protein, are a good source of dietary fibre,  and a good source of zinc (an element very important in the proper functioning of many of the enzymes and proteins in the body). Aside from eating the whole fruit (which may be eaten stuffed with a variety of yummy things like almonds, cream cheese or a more savoury version with tahini or hummus), there is a beverage called "palm wine" that is produced from the sap of the plant in India. It is fermented using traditional methods dating back thousands of years (even today!), and consumed at special occasions. In Pakistan, there is a syrup-like substance that is harvested from the plants and used to seal leatherwares and to prevent pipes from leaking. The sweet sap of the trees might also be condensed and evaporated to produce palm sugar, also called jaggery.

Date palms also have a significant role in religious symbolism. Christians use the leaves of this tree to make crosses on Palm Sunday, a symbol to represent the palm leaves that were scattered on the ground for Jesus' entry to Jerusalem. But, of course, I wouldn't have chosen to profile this plant today if I wanted to talk about its symbolism to the Christian faith; I would have done that near Easter!

Dates are traditionally the first food eaten at the breaking of the fast at the end of Ramadan, a month-long religious fast from sun up to sun down performed by Muslims worldwide, consumed with a drink of water or weak tea. After morning prayers, it is the beginning of Eid al-Fitr (the Sweet Festival), often celebrated with Eid ul-Adar (the Feast of the Sacrifice, traditionally approximately 70 days after the end of Ramadan). The timing of Ramadan changes yearly, but is based on the lunar calendar. The first day of Ramadan is the first day of the ninth month of the lunar calendar, and the first day is determined by the sighting of the crescent moon (if the moon is clouded then by default the month starts the following day). During the month of Ramadan no food items (or other pleasurable things in life) are consumed between sun up and sun down. At the end of the month, the breaking of the fast is celebrated with a big feast and the day of Eid al-Fitr. You would go around wishing your neighbours Eid Mubarak, which (roughly translated) means "Happy Ramadan." Guess what today is? Eid al-Fitr! :)

Eid Mubarak, Happy Ramadan, to all of my Muslim readers!

Sandra's Garden: onion you grow for a flower, not for food

Species name: Allium aflatunense

Common name: flowering onion

Location: Sandra's garden

There are two main species of ornamental purple-flowering onions, and this is one of them. The true flowering onion is native to central Asia but has been spread around the world as an ornamental bulb. It produces these brilliant purple globe-like flowers in the spring, seeds in the fall, and then dies off during the winter to regrow the next year. In most areas, reproduction by seed of this plant is abysmal at best so there isn't a risk of it becoming invasive (the growing season isn't long enough for the seeds to germinate, and by the time spring rolls around the winter has killed the seeds in the soil). There are other ornamental onions that don't have purple flowers that are highly invasive species, so make sure you know what you're planting and what you're getting yourself into!

The other species of purple-flowering onions is the giant onion or Allium giganteum. These two species are relatively easily distinguished because the giant onion has a much more densely packed flower head, which is much larger in diameter. It definitely earns its name! Before we moved we had these planted in our garden, and they were one of my favourite flowers we had there. It's a shame I wasn't into plant photography while we were living there; we had some unusual plants in our garden that would be fun to profile. Both the giant onion and the flowering onion are great species to plant in your garden to attract all sorts of pollinators, but especially bees and other pollinating insects.

The flowering onion and the giant onion are both in the same genus as regular onions (A. cepa, which you can read a bit about HERE), chives (A. schoenoprasum), leeks (A. ampeloprasum), and garlic (A. sativum). I have also profiled another member of the genus Allium a while back, garlic chives (which you can read all about HERE).

Like the carrot family, the onion genus is made up of a group of plants that are edible, and a group of plants that you probably don't want to be eating. Unless you are absolutely certain of your plant's identification, you probably shouldn't decide to eat it! The flowering onion and the giant onion are non-edible plants, meaning they won't make you sick if you eat them but they certainly aren't good. Many wild varieties of onions and garlic are so potent they will actually burn your mouth and cause blisters if you try to eat them, let alone the damage they'll cause to your stomach! Some species of onions are also highly toxic to cats and dogs even if they won't harm humans, so make sure you prevent your beloved pets from munching on these species! Most of the time they'll stay away anyway because the smell is potent enough that they figure out it's not good, but when these plants are young they haven't developed their strongest potency yet and might fool even the most discriminating nose into thinking it's grass.

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.