Thursday, January 31, 2013
Species name: Ephedra nevadensis
Common name: American ephedra
Location: UWO Greenhouse
This rather unassuming species is native to the deserts of North America, hence the Latin name (nevadensis should make you think of the US state Nevada). In a pot it grows to be a rather sad, straggly, sticky thing but in the wild it can be quite large, shrubby, and an important food source for many animals that live there. To me, this is one of the most fascinating plants in the greenhouse, right up there with whisk ferns (which don't look like ferns at all; you can read about them HERE). Ephedra, also sometimes called a gnetophyte depending on the species, is actually a closer relative to ginkgo trees (read about them HERE) and pine trees (read about white pine HERE) than flowering plants, or even club mosses (which it can look very similar to if you use your imagination). In the second image you can see some primitive cones if you look closely, and these are where the pollen and the ovules are produced to make new seeds. They are produced in the stem nodes, usually after new growth has appeared for that year. When a plant undergoes nodal growth, it will produce a bit of a branch and then once conditions are no longer favourable for growth it will produce a terminal bud. This bud will develop once conditions are favourable again and produce new growth and the bud scales will fall off, leaving a scar around the branch or stem which is called a node. This node is also where axial buds are produced, which end up growing into branches (or, in this case, cones).
North American ephedra has been used for centuries as a medicinal species by Native North Americans, and also as a food (although, I can't imagine it being very tasty or very nutritious). For farmers historically and currently in the southern United States desert areas, it is also a very important forage crop for cows, pigs, sheep, and goats.
Medicinally, this is not the same species as the psychoactive plant from which we get the drug ephedrine (but this is also a species of Ephedra, hence the name of the alkaloid). It was originally included in cold and flu medication because it is effective in drying mucous membranes (and so helping with your runny nose), soothing sore throats, and helping you sleep. There are other drugs that are now included in cold medication instead, because of the dirty little secret that ephedrine has. It causes a drastic increase in heart rate, which can have serious complications in some patients (especially those who already have high heart rate as a result of high blood pressure, or vice versa) and even death. In 2007 there was a huge spike in ephedra-related deaths in the United States, and so it was required by cold and flu medication manufacturers to remove products containing ephedrine and pseudoephedrine off the shelves. High-performance athletes were also rumored to use ephedrine as a performance-enhancing drug. Recreationally, ephedrine is a precursor in the manufacture of methamphetamine, and so the sale of ephedrine-containing products was fuelling the underground (and illicit) drug market. There was the suggestion that because ephedrine was such an effective cold and flu medication that it should be a medication you need to request from a pharmacist (but could get without a prescription) in order to obtain, but that wouldn't necessarily stop the ease at which methamphetamine manufacturing labs could obtain it. It has also been used as a diet aid (along with other drugs like caffeine) because it increases body temperature and so should help burn more calories per hour when sedentary, but aside from being incredibly dangerous (death or severe illness requiring hospital stays have been reported in several hundred cases), it also doesn't actually do anything. Only a minor increase in fat burned over a placebo was ever recorded in scientific studies, and certainly not enough to warrant it being sold as a diet aid.
Sunday, January 27, 2013
Species name: Nemanthus wettsteinii
Common name: goldfish plant
Location: UWO Greenhouse
This is one of the few tropical species of plants that grow well indoors that I'm disappointed no one has told me about before a couple of weeks ago. To me, these flowers are just plain awesome. Not just awesome for the fact that they literally look like goldfish (unlike other plants named after animals like the Shrimp Plant; sorry shrimp plant!), but because of their unique adaptations to target their preferred pollinators. The goldfish plant is native to the Amazon and surrounding areas, with the native range stretching from Brazil up to Mexico. This plant, while a very popular indoor plant in the southern United States, is still very common in the wild. It also grows incredibly easily indoors, so the need to return to the wild to collect more plants is rare.
The reproduction of this plant is fascinating. In fact, it hardly ever happens, and never happens sexually in this species. Hard to believe? I agree! But the biology has been well documented, and so here's what happens. The flowers are just an offering to species that need nectar in the wild, which is practically unheard of in the wild. This species of Nemanthus is asexual, meaning the flowers are not produced for the purpose of reproduction. Close relatives of the goldfish plant, who have redder flowers that are less shaped like goldfish and more like tubes, do reproduce via seeds (which requires sexual reproduction) so it appears as if this plant has lost the ability somewhere down the line. Instead, it reproduces asexually by severing its young branches, having them fall off the plant, ideally roll down a hill and root in a new location. In the wild these plants are often epiphytes, meaning they'll grow on just about any surface that they can grab onto (and rarely obtain nutrients from this surface; they get those from the humid air). The goldfish are just swollen sacs of nectar available for any insect or bird to exploit at their will. Hummingbirds, despite the flowers of this species being orange and not red, are still attracted to the flowers and will use it as a preferred nectar source when the flowers are in full bloom. Some insects with biting mouthparts will chew tiny holes in the bottom of the goldfish stomach to allow the nectar to freely flow out of the flower, and drink all they can get before returning to their nest. Other birds will use this same strategy, poking holes in the flowers and drinking the nectar that flows out. Every so often the goldfish plant will make something that looks like seeds when the flowers are spent, but they are sterile and not worth collecting since they will not produce a new individual (bananas are like this also; we call this not being "true to seed").
Like many succulent plants with fleshy leaves, the goldfish plant produces chemicals in the leaves that are mildly irritating to the skin. If you have sensitive skin and are planning on propagating this plant by snapping off leaves and putting them in water to root (it really is that easy to make a new plant!), make sure you wear gloves and you'll be fine. Cats and dogs (and other indoor pets) usually stay away from this plant despite having flowers that look like they would be fun to play with. There must be some kind of scent emitted from the leaves or flowers that lets them know it shouldn't be messed with. Goldfish plants are quite drought tolerant, so ignoring them won't bother them too much. They are also frost-tolerant (reportedly surviving brief exposures of -5 degrees Celsius or about 23-25 degrees Fahrenheit) so forgetting them outside on a cold night isn't a big deal.
A word of warning, however, if you like using these plants as ornamental garden plants in baskets during the summer and have a backyard garden: they carry viroids. A viroid is like a virus, being able to be transmitted from plant to plant when they come in contact (or when the sap of one plant is on the leaf surface of another, where it can enter the leaf breathing pores or stomata). Viroids are present in many plants, and it is believed that some are just the result of a virus that had infected the plant but had mutated to no longer be able to reproduce so gets stuck in the plant as a sort of virus fossil or relic. Some viroids, however, are still able to cause disease in plants, especially crop species. The viroid that the goldfish plant carries causes no symptoms in the plant so you would never even know it had it...until it comes in contact with either potatoes or tomatoes. Then it wreaks havoc. The symptoms in potatoes and tomatoes are quite severe, reducing the yield of crops of these two plants quite drastically. Best to keep these plants away from each other! Viroids cannot be spread through the air, and this particular viroid doesn't last very long outside of the plant, so having them in the same garden is no problem as long as there's a distance between them.
Thursday, January 24, 2013
Species name: Citrus x sinensis, C. medica x C. maxima x C. medica
Common name: sweet orange, ponderosa lemon
Location: UWO Greenhouse
Any kind of citrus is interesting; very few of the types of citrus we grow around the world are pure species and almost all of them are hybrids. The sweet orange, perhaps the most common and the most widely recognized type of citrus fruit around the world, is a hybrid between the pomelo and the mandarin orange (but determining the exact parental lineages are difficult). The only citrus fruits that are pure species are the pomelo, the Mandarin orange, the key lime, citron (not lemons!), Australian limes (3 species), kumquats, and Indian papedas (4 species). Of those 12 species in total, almost 100 hybrids exist that are used for various purposes around the world. An incredible amount of diversity from a small number of species!
The orange is native to Southeast Asia and has been cultivated in China for more than 2500 years. There have been hundreds of varieties developed since then around the world, ranging in habitat from Florida and California all the way to their native range in China. The ponderosa lemon, which apparently makes amazing lemon meringue pies (sweeter than regular lemons, so less sugar is needed in the filling), is native to Maryland in the United States, where it is thought to have originated from a chance hybrid seedling.
Citruses are all genetically very similar, since they originate from such a small gene pool (despite having an enormous amount of morphological variation). This means that many hybrids are all susceptible to the same diseases, and the disease illustrated on both the ponderosa lemon and the oranges is something citrus farmers struggle with every growing season. It's called the citrus canker, and is caused by the bacterium Xanthomonas. It has no effect on humans, and other than affecting the appearance of the fruit it is perfectly edible when it's just the small black spots. Larger black spots can make the fruit inside a bit squishy, but there is no danger in eating it. Unfortunately for the citrus tree, it's not so lucky. When the canker infects the leaves it can cause them to fall off before they are ready, which decreases the ability of the tree to photosynthesize. Less photosynthesis means less sugar production, and a lower fruit yield. Entire groves have been destroyed trying to eradicate the disease, but it can persist in the soil so these attempts have not been successful. On top of suffering from early frosts in recent years, the United States orange industry is suffering from a dramatic reduction in yield in orange groves because of the citrus canker. Does this mean Tropicana orange juice will eventually be produced from oranges grown outside of North America? It's hard to say for sure, but we have reached the point where we need to find a better solution to the problem or else we might lose some citrus hybrids forever. The grapefruit is the most susceptible of any Citrus species, and will probably be the first to disappear.
Wednesday, January 23, 2013
Species name: Punica granatum
Common name: pomegranate
Location: UWO Greenhouse
The pomegranate is native to Iran and Iraq, and has been used as a source of food and medicine by humans for centuries (arguably millennia). It is now widely grown as a tree crop around the world, and is also often now planted as an ornamental species both for its flowers (which are spectacular), the fruits (yum), and the bark (twisted and knotty; it's also quite spectacular-looking). There are even cultivars of pomegranate that were created in greenhouses specifically for their flowers, and the fruits don't even form. Seems like a waste of a pomegranate plant to me!
Pomegranates aren't just known for their edible seeds. Actually, it's not even the seeds that you consume! Like in some gymnosperms or cone-bearing plants, the seeds have a fleshy covering around them called an aril (you can read more about gymnosperms with an aril HERE and HERE). This aril is the red, juicy bit around the tough white seed. It's not that the seed is bad for you (unlike in the examples above, where the seed is deadly), it's just that the plant wants small animals to consume the aril with the seed inside, then poop the seed out intact. This gives the seed a nutritious medium to grow in, and it ensures that the seeds are dispersed away from the plant (unless the plant has the misfortune of having the animal leave the plant, then return to it and deposit the "organic matter").
For centuries, the pomegranate has been used as a medicinal plant, even before we started touting its "anti-oxidant" properties. Indian people are the most well-known for their use of pomegranates in Ayurvetic medicine going back at least a millennium (likely significantly longer than that). The rind, or the outside of the fruit (the "skin" that most people throw out) was used to make a type of tea that would be consumed to stop intestinal discomfort like diarrhea and problems related to dysentery. The juice and seeds of the plant would be consumed in a tonic to soothe sore throat and treat heart palpitations, as well as a treatment for heart attack. The seeds themselves would be consumed as an agent inducing abortion and as a contraceptive. The juice of the arils also has a reported use when applied topically on the skin to clear blemishes and help fade scars and rashes. There are a boatload of health benefits that herbal medicine practitioners in North America and Europe will tell you that the pomegranate has. First, it is claimed that it will reduce cholesterol and unblock arteries and veins in your heart (and reduce other risk factors for heart disease). Next, it's claimed that it will prevent the formation of cancer tumours due to its anti-oxidant properties, and will halt or reverse the growth of tumours that are already present. Lastly, it's claimed that pomegranate juice is an effective anti-bacterial chemical and will prevent infection in wound sites as well as preventing bacterial growth in your mouth when you consume it.
So what claims have been substantiated with actual evidence? None. There are suggestions, correlations, that pomegranate juice prevents (to some degree) plaque formation on your teeth by inhibiting bacterial growth. But remember, this is the bacteria in your mouth, not the bacteria on your skin. This doesn't mean it will prevent infection on your skinned knees. There is NO evidence that the anti-oxidants present in pomegranate juice will have any effect on your circulatory (or other) system. None. Don't get fooled by claims that there is evidence it does anything, because it doesn't. In fact, the leading brand of pomegranate juice, POM Wonderful, was sued for making illegal health claims on their product's label. The claims have since been removed. That being said, there are currently 32 enormous scientific trials underway in the United States testing the reported effects of pomegranates on different conditions. You can find all of the clinical trials on the National Institutes of Health website (NIH Clinical Trials), and what stage of the trial has been completed. None of them have published data (but it will be coming).
Monday, January 21, 2013
Species name: Nepenthes sp. (a hybrid)
Common name: pitcher plant, monkey cup
Location: UWO Greenhouse
This species of pitcher plant is tropical in origin from somewhere in the Old World Tropics (the complete range of all of the species of Nepenthes is included at the bottom of the blog post courtesy of Wikipedia). The label on the plant says it's a hybrid Nepenthes, but the label corresponds to a hybrid that looks nothing like the pot hanging in the greenhouse. Perhaps the pictures on the internet are wrong...there aren't many of them. For now it's probably just safe to say it's a hybrid and leave it at that. Nepenthes species (there's about 140 of them worldwide) are almost all threatened, endangered or critically endangered. There are only a small handful that the IUCN and CITES consider of "least concern," but there are also quite a few that are considered "data deficient." For those of you considering going to graduate school, here's a project idea: catalogue the pitcher plants in Borneo and Sumatra, and come up with a monitoring program that involves going back into the bush and re-counting populations every year to judge reproductive abilities of a single plant and of a colony, plus motion-sensor video monitoring of the traps for what they're catching and what's consuming or destroying the plants. Mix that with cataloguing indigenous knowledge of the pitcher plants and what they're used for, and you've got yourself a PhD! I wish I had of thought of it sooner...sounds like an awesome time.
I profiled a native Canadian species of pitcher plant a while back (for a refresher, you can read all about it HERE), and if you remember what that species looked like you can see that the pitcher traps or pitfall traps are very different than what grows from Nepenthes plants. First of all, Sarracenia traps grow on the ground with the rest of the plant in boggy, swampy areas while Nepenthes grow in rocky, mountainous areas and the traps hang off of the leaves. The traps of the North American pitcher plant have curled lips that funnel rainwater into the trap (and is also very slippery to funnel bugs in, too), while the Asian species have a lid to prevent rain water from overflowing the trap and shelters the traps from falling debris. And the best part? The two groups aren't related to each other at all! The pitfall trap has evolved at least two separate times over evolutionary history, each time converging on what, today, looks like a nearly identical structure. The functions are identical as well; both groups have traps to catch insects to digest, but also act as vital breeding habitats for insects with aquatic larvae like mosquitos.
One of the biggest differences between the two groups, and the main characteristic that should lead you to believe that the two groups aren't related, is how the traps are formed. In Sarracenia, the traps are basically the leaves. The traps start to grow out of the rosette stem (a stem that is very reduced in size, and never reaching very high above the surface of the ground; the leaves and other plant organs radiate out from this point like the petals of a rose) as photosynthetic organs, and start to produce digestive liquid on the inside once mature. If the plant is going to produce normal leaves, they are completely separate structures that grow out of the rosette at the base of the plant. In Nepenthes, the traps actually grow off of the already-existing leaves. The leaf grows out of the stem rosette, photosynthesizes for a while, the starts to grow this long projection from the tip of the leaf. This projection continues to grow for up to 2 meters, eventually developing into a trap at the tip. Once the liquid inside the trap has been consumed by digested prey and the plant has absorbed all of the released nutrients, the trap and the entire leaf dies and falls off (very similar to the way that a Venus fly trap operates).
If you would like to start a Nepenthes collection in a greenhouse or in your home, it's entirely possible. There are enormous collections of these species in greenhouses around the world, and new cultivars and hybrids are being created every few years. The trick is how the plants were obtained. Collecting seeds and propagating the plants from seeds is illegal according to international biodiversity laws. If you are caught doing that, or caught with plants propagated this way, you may go to jail. This probably wouldn't be good, so make sure you know where your plants are coming from. The good thing is that the leaves readily regrow plantlets in tissue culture when exposed to the right hormone concoction (many plants are grown in tissue culture; tobacco being the most common). This means that only a tiny portion of a leaf is needed to grow the first plant (less than a square centimetre), and all other plants can be made from this parent plant. The downside is that all plants are clones, but if you're just growing it inside it doesn't matter much. If you're growing them to replant in the wild, this would be an enormous problem because of pathogen threats to genetically uniform populations. Make sure you ask your source of Nepenthes how they were grown and where they were collected from! If the person doesn't know, don't buy it.
The native habitat distribution of species of Nepenthes (courtesy of Wikipedia)
Sunday, January 20, 2013
Species name: Kalanchoe beharensis
Common name: elephant ear kalanchoe
Location: UWO Greenhouse
Contrary to my wishes, the elephant ear kalanchoe (having Latin names as a common name can be incredibly confusing; Kalanchoe refers to the genus, kalanchoe refers to any plant that looks like it belongs to the genus, whether it does or not) is native to Madagascar. Based on the shape of the leaves, I figured that they looked more like an Asian elephant than an African elephant, and so I wanted badly for this plant to be native to India. Not so. Ah, well. This species of Kalanchoe was once widely distributed across the entire island of Madagascar, but now exists only in small areas (but in those small areas it is still very abundant). It has been introduced to many areas around the world including Mexico, South Africa, and the Himalayas where it has been naturalized and exists as an integral part of their arid, desert ecosystems. This plant is a succulent, meaning it is drought-tolerant and stores water in its leaves for use during times when water is not readily available. Succulents actually do better when you let the soil dry out completely between waterings, and over-watering is the leading cause of death of indoor succulents (that sounded very coroner-like...). In fact, if you are prone to neglecting house plants, this plant is definitely for you; it can survive for two weeks during the height of summer with no water, and at least two months during the winter!
Different species of Kalanchoe are known not for their foliage or for their flowers, but for their method of reproduction. Unfortunately, this species also didn't read the book about rules kalanchoes have to follow so it very rarely reproduces this way. Most kalanchoes produce structures called foliar embryos at the edges of their leaves, in the indentations or margin waves. These foliar embryos are produced asexually (they are clones of the parent plant), and develop on the edge of the leaf using resources from the parent plant until it is ready to grow on its own. Depending on how much water is around, this could even be until the embryo has four or five fully-developed leaves and a handful of roots. It's quite a spectacle to see, and I'll profile another species of Kalanchoe another time that produces spectacular amounts of these foliar embryos. They are often sold in nurseries and greenhouses, which I never understood. Why buy the plant if you can get the embryos for free?! I'll admit, guilty as charged--that's how I obtained my Kalanchoe that we had in a south-facing window until we moved. Various species of Kalanchoe can reach heights of up to 12 meters, and regularly grow indoors to 6 feet or more if given a big enough pot. Even in a 6" pot, my kalanchoe was enormous, and produced so many embryos they would regularly be all over the carpet. If you want a clean houseplant, this one is not for you!
The dense surface hairs on the leaves and upper stem of these plants serve two purposes. The first is a method of decreasing water loss from the leaf of the plant. The hairs create a micro-climate at the leaf's surface that is humid and warm, ensuring that any water around the leaf condenses on the hairs and can be used by the plant. Creating a leaf micro-climate is common of succulent and other desert species since losing too much water from your leaves will definitely lead to the death of the plant in such a harsh climate. The second reason for the leaf hairs is to serve as a defence system for the plant. Since the leaf tissues are so juicy, any herbivore looking for food and water would target succulent plants first. They cannot afford to be eaten, so they produce surface hairs that are more like spines or daggers to a small insect. This is actually incredibly effective; if you mutate the genes responsible for producing surface hairs on the leaves, the plant is completely consumed by insects and other small herbivores (and even some big ones like omnivorous lizards). The surface hairs themselves deter about 95% of all predators, and the additional chemical they pack into the hairs deters the rest: silica. If you've ever had an accidental mouthful of sand, you'll understand why nothing would ever want to eat these plants!
Saturday, January 19, 2013
Species name: Mimosa pudica
Common name: sensitive plant
Location: UWO Greenhouse
The sensitive plant is native to Central and South America, where it is so common you might mistake it for grass in some areas if you're not paying attention. It has been introduced to other continents around the world, and it has become invasive in Australia, South Africa, Tanzania, and many islands in the South Pacific (along with other continental countries in Asia). It has also been introduced to many countries other than just South Africa and Tanzania in Africa, but it does not seem to become invasive there. When I was in Panama, the hotel I was staying at looked out over the Chagres River (the main river feeding the Panama Canal), and between the hotel and the river was a big flood-plain covered in what I thought was grass. I went and took a walk one day and you could literally see where I had wandered around, since all of the leaves were closing behind me as I walked. It was a neat experience!
The sensitive plant is called the sensitive plant for a reason; it is sensitive to light, temperature, electrical charge, and touch. It is not just a common garden plant in some areas for these reasons; it has become one of the most widely sold tropical indoor plant species in recent years. When touched, the leaves of the plant very quickly close; the difference in time between the photo with the leaflets fully open and them fully closed was only a few seconds. After a couple of minutes the leaves open back up again. This is accomplished through the rapid movement of water out (in the case of the leaflets closing) or in (in the case of the leaflets opening again) to the plant cells. The plants, like animals for generating never impulses which result in movement of muscles, have the ability to rapidly pump potassium ions into the the spaces between cells, causing a change in osmolarity of the cells. Normally the osmolarity of the cell is slightly higher than the osmolarity of the space outside the cells; this ensures water is constantly being diffused into the cell, keeping it turgid (which would result in crisp lettuce instead of floppy, gross lettuce). When potassium is pumped into the spaces between cells, water moves across the cell membrane and the cell wall into the intercellular spaces to try to equalize the osmotic pressure. This causes water to escape rapidly from the cells, the cells collapse, and the leaflets close. Once the potassium is gradually cleared away from the intercellular spaces, the water is free to diffuse back into the cells, and the leaflets gradually open back up again.
Being able to open and close your leaves is a great response to have, but only if you can use it properly and with purpose. Pumping potassium into a space that usually has very little takes quite a bit of energy, and using all this energy for no reason probably isn't smart if you want to survive. So what would possess a plant to close its leaves in response to touch? What would the point of that be? Well, you can see some clues in the bottom photograph. The varieties of plants grown in greenhouses for sale as tropical indoor plants have been bred to have lost their spines. Wild varieties of the sensitive plant have tiny spines all along the underside of their leaves, and all along the petiole of the leaf. When the leaflets close, they expose these spines to whatever has cause the leaf closure, and this is hopefully an effective defence for the plant. Normally this works well; the sensitive plant has become so abundant in pastures because cows refuse to eat it (the spines mixed with the fact that it is mildly irritating to the gastrointestinal system of cows, sheep, horses and pigs) and insects stay away from it. When I was walking through the Mimosa field, I was happy I was wearing shoes! My toes would have been very unhappy if I wasn't.
The sensitive plant was once planted on purpose in areas of Africa, Asia and Australia (and the reason why it has become so invasive). Because it is part of the bean or legume family, it has nitrogen-fixing bacteria nodules along its roots. These nodules, containing the bacterium Rhizobium, convert atmospheric nitrogen (a form of nitrogen plants cannot use) into a biologically-active form of nitrogen. This is great for agriculture soils, since traditional crops like corn, wheat and rice all deplete the soil of nitrogen very quickly. If you can rotate your crops with a legume, you can put the nitrogen back into the soil for the next growing season. When the plant has the ability to escape and grow in the wild on their own, and has no known herbivores that will target it, it becomes dangerous to the environment. Eradication programs are now in place in Australia, where the sensitive plant has become especially problematic.
The toxin in the leaves of this plant, called mimosine (an alkaloid), is toxic to a few species of insects and so has been looked at in recent years as a natural insecticide. I'm not sure where the research stands on this, but it is produced in such small quantities in the plant that a method of synthesizing mimosine in the lab would have to be accomplished before it had any real industrial applications. Extracts from the leaves containing mimosine have also been shown to be a natural anti-venom to the deadly toxic monocled cobra snake, and so there may also be a medicinal application for this plant.
Friday, January 18, 2013
Species name: Coprinopsis lagopus
Common name: harefoot mushroom
I realized it's been quite a while since I've featured a fungus or fungus-like organism on my blog, and what better day to feature one than on Fungus Friday?!
The harefoot mushroom (the common name apparently comes from the appearance of the young mushrooms growing up from the ground; sure doesn't look like a rabbit foot to me) used to be considered a species of Coprinus, back when everything that produced black spores and digested itself when fully mature was a Coprinus. Now we know that this trait is actually shared between a few genera of fungi, and not all of them are related to each other. One way that seems to be effective to tell Coprinopsis from Coprinus is whether the fruiting body is edible. If edible (but with dangers; I will discuss it below), it is much more likely it belongs in Coprinus, where species of Coprinopsis are considered inedible; they won't kill you or make you sick if you eat them, but they certainly aren't tasty. Many "inedible" fungi also contain gastrointestinal irritants that will make your digestive system revolt against you for a few hours but with no real danger of severe dehydration (this is not true for other species of fungi labelled "poisonous"!).
Deliquescent fungi are often accused of distributing their spores through their auto-digest slime, since there seems to be quite a population of flies that swarm around them if left alone. This statement is most often associated with the shaggy mane, Coprinus comatus, which gives a spectacular auto-digest show on lawns across North America and Europe in the late summer and early fall. If you sample that black, blobby mess and look at it under the microscope, it shouldn't be surprising to note that there are very few, if any spores, present in the mess. Why shouldn't this be surprising? Well, two reasons. The whole point of a fungus producing spores is to disperse its future offspring to more suitable habitat (in fact, some fungi don't even produce mushrooms until they have completely depleted the resources in a given area). Depositing your spores directly beneath you in hopes they'll have a better life than you are currently having is a pretty silly idea! You would be giving your offspring a disadvantage before they even got off the ground (literally). The other clue this shouldn't be surprising is on the stem, if you look closely. Normally, the stem of both Coprinus and Coprinopsis is pure white (some are yellow or orange, but never with black spots). If you look carefully about 2/3 of the way down the stem of the second image, you can see a black fluff on the stem. If you were to take a tiny sample of that with tweezers and look at it under the microscope, you would see that those are the surface hairs of the stem absolutely covered in the black spores of the mushroom. The spores, produced on the gills, are blown away in the wind as soon as they are mature. If there are no air currents at the time that a spore detaches, it follows the rules of gravity and falls straight downwards, sometimes getting caught on surface hairs on its way to the ground. By the time the cap of the mushroom starts to be digested by the fungus' own enzymes, almost all the spores have already dispersed. Amazing how some fungi can trick us! The third picture, one of my favourite pictures I've ever taken (as proof, it's the lock-screen image on my iPhone), shows how the mushroom's gills are the first thing to turn black, and that's likely just the colour of the spores being displayed as a change in colour of the gills.
Species of Coprinus are eaten by people in North America and Europe, and will likely remain that way for quite a long time. Should you choose to eat a shaggy mane or a close relative, some words of caution. All of these species, whether Coprinus or Coprinopsis, deliquesce very quickly after being picked. Unless you want to eat a black soupy mess (I've heard it tastes the same, but looks more like black vomit than a mushroom), you must eat them very soon after picking. Any wild mushroom, no matter the species, MUST be cooked before consumption. Many species of fungi (including the common button mushroom available in grocery stores) contain compounds that have been shown to be carcinogenic. These compounds are very unstable when heated, so cooking will break them into harmless chemical pieces. The shaggy mane is famous for containing the chemical coprine, which mimics the alcoholic drug antabuse. When mixed with alcohol, species of Coprinus will cause spectacular projectile vomiting that makes the victim feel like they would rather die than vomit any more (the whole point of antabuse; it certainly is not potent enough to kill anyone, but will make you rethink mixing it with alcohol!). If you're going to consume any kind of wild mushroom, it's always best to make sure the meal is alcohol-free. It's also probably best to avoid alcohol for the next few meals; some other species that also have antabuse-like properties take days for their toxins to clear from the digestive tract and can induce vomiting 48-72 hours after consumption!
Wednesday, January 16, 2013
Species name: Mandevilla sanderi
Common name: Brazilian jasmine
Location: UWO Greenhouse
Brazilian jasmine is native to (you guessed it) Brazil, and until recently was considered part of a separate genus from the rest of the Mandevilla species in the genus Dipladenia. Most of the species currently classified in Mandevilla are native to Ecuador; this is one of the only species that's not. It's also one of the only species in the genus that's not critically endangered. It is still relatively common in the Brazilian rain forest, although the forest itself is decreasing in area by about 5-10% per year, so it will also soon be at risk. The common name of this plant is sometimes Chilean jasmine, but that common name actually refers to another plant, native to Argentina (yet another reason why common names of plants bother me...)
One of the characteristics of this plant that make it so attractive to gardeners (especially those with an indoor green thumb) are the strongly scented flowers. When in the appropriate location (in full to partial sun), these vines can reach heights up to 10 meters tall if given a support system in one growing season. If you want to encourage bushier growth, pruning the plant back almost to ground level every fall to encourage new growth in the spring would be best. The flowers can be tricked into being produced repeatedly during the growing season if the old flowers are pinched off (also called dead-heading). When grown in a container (either indoors or outdoors), it will rarely reach a height taller than a couple of meters.
There are no reports of this plant being toxic, but also none of it being edible. It is sometimes used in the perfume industry because of its scent, but doesn't have any other value aside from an ornamental plant. In the garden it will attract hummingbirds and butterflies because of the shape and colour of the flowers (and also a few bees...!).
Tuesday, January 15, 2013
Species name: Stanhopea sp.
Common name: Stan orchid
Location: UWO Greenhouse
All of the plants in a greenhouse typically are labelled with species name, family that the plant belongs to, and the common name (sometimes this is omitted). In greenhouses where plants are actively being propagated, sometimes all of the pots are put together that are the same species, and the "master plant," or the mature plant from which all the propagules were generated, is the only one that's labelled. Normally this doesn't pose a problem...until species are so similar they're indistinguishable. The hanging pot this plant was in wasn't labelled, but one a little further down was (but that one didn't have flowers). After looking up that species online, the flowers are completely different between the pot that had the label and the one that had the flowers, leading me to believe the species is different. On the bright side, it's in the right genus!
Most of the 60 (or so) species of Stan orchids are native to Central and South America, and a good number of them are at risk or threatened due to their very narrow native ranges, and the deforestation occurring through much of Central and South America. Some of them, like Stanhopea wardii, are still very common and are also popular ornamental species (that come in multiple varieties with different coloured or patterned flowers). Many of the species with this genus don't exactly smell pleasant, but they don't smell gross, either. A great deal of Stan orchids produce an odor to attract very specific pollinators. The odor produced mimics the sex pheromones of the insects, so instead of coming to the flower thinking there is nectar to drink they come to try to copulate with it. It might be mean of the flower to coerce an insect into thinking it's a member of the same species, but effective for the flower in pollination. A neat mechanism, and one that is repeated across many orchid species (and other flowering species of plants in general).
The Stanhopea genus is named after the first Earl Stanhope (James), the principal minister to King George I in England. The title of Lord Stanhope is passed down through the first-born son. Many of Lord Stanhope's children are also prominent figures in history (many of whom were politicians, but one was very important during the French Revolution), so having a plant named after all of them is probably fitting.
Monday, January 14, 2013
Species name: Acalypha hispida
Common name: chenille plant
Location: UWO Greenhouse
The chenille plant, also called the Philippines Medusa and the fox tail, is native to a set of small islands off the coast of Australia, between Australia and Indonesia. It has now been domesticated throughout much of the world with a warm climate year-round (it is not frost-tolerant) such as the southern United States, Mexico, Brazil, and Belize. It is still common throughout all of its native range, and much of its naturalized range.
The chenille plant can almost be considered a domesticated plant in some areas. It no longer does well in the wild in some spots it has been introduced because we (as humans) have subjected it to artificial selection to favour traits we like. The inflorescences, while usually having quite a bit of "fur" on them, were much shorter and much less hairy in the wild ancestors than the ornamental varieties sold today. This is considered artificial selection as this would never have happened naturally in the wild; increasing the hairiness of the inflorescences actually decreases the plant's ability to disperse their seeds. Not a good thing if you're the plant! There are also some cultivars of ornamental plants that have orange and even yellow inflorescences as opposed to the "natural" red colour (but this has also been artificially selected for increased intensity).
The family that this plant belongs to is called the Euphorbiaceae, or the spurge family (sometimes the euphorb family). The easiest way to determine if a plant belongs to this family is if it produces a milky white latex from the leaves when they are broken (which you can see dried on the leaf's surface in the third photo). If so, chances are much higher it belongs to this family than not. If you have sensitive skin like I do, you'll also probably find out the hard way that euphorb latex is extremely irritating to sensitive skin, completely separate of whether or not you have a traditional latex allergy. This should probably suggest to you that perhaps this plant shouldn't be consumed if it has the ability to burn your skin on contact, and you would be correct. The chenille plant is deadly toxic to small animals, and would make any human that tried to eat it very sick. If you have cats, you might want to reconsider before buying this plant (either to plant outside or as an indoor plant); my cat would mistake the inflorescences for cat toys in a heartbeat and it would likely be a deadly mistake.