154

Hours of Operation

Winter Hours

Louis Riel Day (Feb 19)
11 am - 5 pm

Mondays
Closed (except Holidays)

Tuesday to Friday
10 am - 4 pm

Saturday & Sunday
11 am - 5 pm

Click for Holiday Hours

Blog

Botany

Botany

02/12/18

The art and science of diorama making, part 1: Perfectly imperfect

When people come to the Museum and see our dioramas they are usually impressed with the majestic, taxidermied animals in them. But what they really ought to be impressed with are the plants. I find it amazing that the trees in the elk diorama are perpetually in the process of shedding their leaves.

The leaves on these aspen (Populus tremuloides) trees never fall off because they are glued on.

Anyone familiar with Manitoba’s forests and prairies, know that the plant species in our dioramas are the same ones that occur in the wild. That’s because, for the most part, they ARE real specimens. Although fake plants are readily available in stores, they are almost all tropical species that don’t occur in Manitoba. Further, mass-produced fake plants are usually too perfect to be entirely realistic. Nature is not perfect. Every animal (including you) and every plant is imperfect with discolorations and asymmetrical features. Real spruce and pine trees never look as perfect as artificial Christmas trees.

You won't find any pitcherplant (Sarracenia purpurea) models at Home Depot! That's why we have to make them ourselves!

To create our dioramas, real plants and fungi were identified and collected from natural areas (with permission from the landowner of course) and then pickled, glued and preserved in various ways. This preservation process, which takes many months to do, is essential to make it look like the plants are still alive; taking short cuts would destroy the illusion that you are in a real place. There are various problems that have to be overcome to ensure that our plants look right. For one, wood has a tendency to dry out and crack when you bring it into a building. That is why we have to pickle our trees to prevent this from happening. Another thing that happens when you bring a tree into a building is that the leaves fall off, unless it is in a pot and being watered. To prevent our leaves from falling off, special glues are applied to ensure they stay attached. We also need to make sure that the “floor” of the diorama looks real. We do this by attaching pieces of real sod to Styrofoam blocks that can easily be installed, removed and repaired.

This piece of sod from the Ukrainian Rye Farm diorama in the Parklands Gallery was temporarily removed for maintenance.

Anyone who has seen a dead plant knows that it turns brown as it dries out. So why are some of our diorama plants still green? The answer is paint: lots and lots of paint. That, and the infinite patience of a host of leaf-painting volunteers. That’s right someone painted every single one of the tree leaves in our dioramas, as well as many shrub, moss and grass leaves too. To make sure that the plants were painted the right colour, the Diorama Artist closely examined all the plants while they were alive, determined exactly which colour they were, and then blended paints to achieve the same colour. As painting plants is a lot of work, fall (e.g. elk diorama in the Parklands Gallery) and early spring (e.g. Bison diorama in the Orientation Gallery) dioramas are much easier to create because most of the vegetation is dead and brown at that time of the year anyway.

Every single leaf on the trees in our dioramas were hand painted!

But not all the parts of a plant or fungus can be dried and painted. Plants in summer scenes have to possess flowers and fruits but these structures usually look terrible when they are dried out. So what do we do in those situations? In my next blog I will describe the process used to create plants from scratch.

01/22/18

Museum’s Charlie Brown Tree Gets “Spruced Up”

This January what I like to call the Museum’s “Charlie Brown Christmas Tree” in the Arctic/Subarctic gallery, got polished up with some new paint and a new background. It’s still lopsided as ever (it did grow in the arctic after all) but now it has some friends in the background. This often missed mini-diorama is about Manitoba’s treeline: the part of the province where trees start to disappear.

The treeline exhibit with the old background. (c) MM

 

The black spruce (Picea mariana) tree in the diorama is known as a “krummholz”, a German word that means “crooked wood”. Krummholz trees grow in environments that are extremely difficult to survive in, including the far north and the tops of mountains. The trees in Manitoba’s north are subjected to strong winds that blow snow and ice around, which tends to kill the buds on the windward (northern) sides of the trees. The buds that do survive tend to be lower down on the tree, where they are protected by snow in the winter or on the southern side of the branch where it is marginally less nasty. This gives the trees their unique, flag-like appearance.

The "spruced up" tree with a new background. (c) MM

Woody plants in the far north grow very slowly due to the short growing season and poor fertility of the soil. This is why, despite the small size of krummholz trees, they are often quite old. A tree only four or five centimeters in diameter could be over 50 years old! The same tree species growing near Winnipeg would likely be at least ten times as large.

As part of a project to add new murals to the oldest galleries, the wall behind the tree was repainted and covered with a mural of other krummholz trees in northern Manitoba. The little tree was then given a good dusting, fresh paint on some of its needles and some new plants at the base by our diorama artist. It is the first of several murals in the Arctic/Subarctic and Boreal Forest Galleries that will be added soon.

12/06/17

Oh no, mistletoe

Although Christmas is considered to be a “Christian” holiday, many of the rituals we associate with it, such as kissing under mistletoe, are actually pagan in origin. European mistletoe (Viscum album) was considered to be a magical plant by Druidic priests because it mysteriously grew on the branches of trees without its roots reaching the soil. Further, it stayed green in winter, and produced its berries in November and December when other plants were going dormant. Druidic priests collected mistletoe from oak trees to hang in homes in the hopes that it would ward off evil. The custom of kissing under it might have grown from a Scandinavian myth regard Baldur, the god of peace (Foster and Johnson, 2006). The myth states that Baldur was slain by an arrow made of mistletoe but then brought back to life. To commemorate this resurrection, mistletoe was given to the goddess of love, who declared that anyone passing under it should receive a kiss so that the plant would be associated with love not death.

European mistletoe (Viscum album) growing on its host tree, an apple (Pyrus sp.). From Wikimedia Commons

In reality European mistletoes’ seemingly magical appearance is actually due to the fact that it is a semi-parasitic plant on coniferous and deciduous trees. This means that while it has leaves that can photosynthesize its own sugars, it steals water and minerals from a host plant. It is known to infect about 200 different tree species! European mistletoe berries are an important source of food for birds (they are poisonous to people though), which disperse the seeds throughout the forest in their feces and by rubbing the sticky seeds off their beaks. Seeds that land on the branches of trees will germinate there, producing a special root that penetrates through the bark so it can tap into the trees’ sap. Trees infected with European mistletoe are weakened but not usually killed by it. Oak mistletoe (Phoradendron leucarpum), grows in the eastern parts of the United States and Mexico. It is very similar in appearance to European mistletoe but only infects deciduous trees. Oak mistletoe is the species that you can buy fresh in some parts of Canada at Christmas time, although it is not native here.

American dwarf mistletoe (Arceuthobium americanum) growing on a pine tree. From Wikimedia Commons.

Manitoba has two species of mistletoe: American dwarf (Arceuthobium americanum) and dwarf mistletoe (A. pusillum). Unlike European and oak mistletoe, these species are complete parasites so they do not produce any green leaves. For this reason they are not particularly attractive, consisting mainly of yellowish-green stems with tiny flowers that mature into bluish berries. The fruits of Manitoba’s mistletoes explosively eject their seeds at speeds up to 80 km/hour, travelling up to 18 metres away from the parent plant. Since the seeds are coated in sticky mucilage, they will adhere to whatever surface they hit, potentially infecting another tree. As these species cause “witches’ brooms” on the conifer trees that they parasitize (usually spruce or pine), and eventually cause tree death, they are not looked upon fondly by foresters. Trees infected with mistletoe become deformed, and are less useful for commercial timber.

Herbarium specimen of a Jack pine (Pinus banksiana) tree infected with dwarf mistletoe (Arceuthobium americanum). TMM

Regardless of whether you love or hate mistletoe, you have to admit that they are among the world’s most interesting and unusual plants.

Reference
Foster, S. and R.L. Johnson. 2006. Desk reference to nature’s medicine. National Geographic, Washington, D.C.

11/01/17

WHY I KNOW NOTHING ABOUT HOUSEPLANTS

When people find out I’m a botanist they always start asking me about their houseplants. Unfortunately, I really don’t know much about houseplants as they are pretty much all tropical or desert plants, not native species, which is where my expertise lies. Not wanting to seem rude by saying “how should I know what’s wrong with your stupid Ficus”, I began thinking about the things I could say using my knowledge about plant ecology. The best advice I was able to come up with is to learn about where your houseplant comes from originally and use that information to adjust how you treat your plant. In this spirit, here is some good general advice. Obviously, the best advice to follow is the instructions on that little tag that comes with the plant. But if you’ve lost the tag and don’t know what species is, there are a few things the plant can tell you about itself.

Jade plant (Crassula ovata) is a succulent that does not like to be overwatered.

1. Thick, fleshy leaved plants
Plants with thick, fleshy leaves or stems and spines, are succulents. This means they are probably adapted to dry, desert environments where they might go without rain for months at a time. When it does rain, the plants suck up the water quickly, often storing it as a kind of gel. These plants thrive on neglect and are excellent if you travel a lot as you can leave them for weeks at a time without watering them. In fact, overwatering can kill them, as can the way you water them. Succulents don’t like their “feet” (i.e. roots) wet for very long. To water a succulent properly, wait until the leaves/stems get wrinkly-this means they are using their stored water to live. Place your pot in a sink, shower or bathtub, pour in a whole bunch of lukewarm water and let it drain through the hole in the bottom overnight (DON’T use a pot with a water tray at the bottom). I water my succulent pot only about once a month. Also succulents love sun so they typically need a southern-facing window to be happy.

Examples: Century plant (Agave), aloes (Aloe), jade plant (Crassula), Euphorbia (Euphorbia), burrow’s tail (Sedum), and cactuses

Peace lilies (Spathiphyllum) will tolerate low light. From Wikimedia Commons.

2. Wide, dark green, thin-leaved plants
Plants with wide, dark leaves tend to be forest floor dwellers, vines or tropical bromeliads. Since very little light penetrates to the forest floor they need big leaves to intercept enough light. Putting such a plant in a hot, southern window will probably make it miserable as it will get the botanical equivalent of sunburn. They may drop their leaves and grow newer, smaller, paler ones in response to these conditions. These types of plants typically do OK in northern-facing windows or indirect light. They generally also hate drying out so they should be watered fairly frequently to keep the soil damp. A word of caution: some of these plants like humid conditions and may not grow well in a dry house; they might be happier in a terrarium or near a humidifier.

Examples: Chinese evergreen (Agalonema), cast-iron plant (Aspidistra), pothos (Epipremnum), Chinese fan palm (Livistona), peace lily (Spathiphyllum), bromeliads, ferns and many orchids

Spider plants (Chlorophytum comosum) like it a bit sunny. From Wikimedia Commons.

3. Narrow, pale green or silvery-leaved plants
Plants with narrow leaves are often from sunny, somewhat dry habitats like savannas, grasslands and open forests. They generally prefer east, west or south-facing windows and may do OK with indirect light. Unlike succulents, they typically need moister soil conditions although they will still need good drainage.

Examples: Spider plant (Chlorophytum), umbrella plant (Cyperus), dragon plant (Dracena), date palm (Phoenix), yuccas (Yucca)

That’s about all I know about houseplants. Good luck not killing yours!

09/20/17

What a difference a year makes

One of the first papers on pollination I tried to publish got rejected because I had data from only one field season. So I withdrew the paper and did another year of research. But why is having two years of data so important? It is mainly because the world is a messy place.

The summer blooming showy goldenrod (Solidago nemoralis), here being visited by a bee fly, was less abundant than the spring blooming flowers.

This year I conducted a second year of pollinator surveys at the Yellow Quill Prairie Preserve. One thing I learned was that the flowering season starts much earlier than I had anticipated. Initially I thought August would be the month with the most flowers blooming but now I know that May has more due to the abundance of common chickweed (Cerastium arvense) and three-flowered avens (Geum triflorum). Further, there were several plants that I did not think were particularly attractive to pollinators. In 2016 I observed only a few pollinators visiting gaillardia (Gaillardia aristata), and concluded that it was probably an unimportant plant. However, in 2017, I observed this plant at peak bloom and, after averaging the data, discovered that it was actually one of the most frequently visited plants. So without two years’ worth of data, the importance of some species would have been underestimated.

At Yellow Quill Prairie, common chickweed (Cerastium arvense) and three-flowered avens (Geum triflorum) were abundant in May.

When looking at data is important to understand what the word “average” really means; it can be a bit misleading because it implies that most things are the same. In fact, it could mean that things are usually different. Take something like the number of times pollinators visit a group of plants. If I say the average number of visits per hour is 18 you would think that means you would typically see three visits every ten minutes all summer long. But that’s not what happens at all. On cool, windy days I sometimes saw less than one visit every hour. On warm days however, 25 to 50 visits an hour was typical. So the average is actually the number in between these extremes and not really representative of what you would see on any given day. Only by collecting lots of data over long periods of time can you really get a good idea of what is going on in an ecosystem.

I finally saw bumblebees visiting Gaillardia (Gaillardia aristata) in 2017.

So why do we see such extreme fluctuations in nature? Certainly the weather, time of year, land usage and life cycles affect plants and pollinators but there are also other factors that we just don’t entirely understand. In fact, ecologists rarely expect to find a reason for all the variability they observe in a system. Long-term and multi-year studies are valuable because they help us see beyond the noise of the data. An accurate picture of how ecosystems work, and might adapt to environmental changes, cannot be assessed without this type of research.

This research is made possible by funding from the Nature Conservancy of Canada and the Manitoba Museum Foundation.

07/12/17

I always feel like something is watching me

Usually when I do field work I’m by myself. But sometimes I get the feeling that I’m being watched. The main things that have been watching me this year are the cows. The Yellow Quill Prairie Preserve, owned by the Nature Conservancy of Canada, is sustainably grazed by a herd of cows. Aside from using some of my plot stakes as scratching posts and knocking them down, they generally leave me alone and I leave them alone. Sometimes, though, they get a little curious and stare at me with those slightly vacant eyes as if they are expecting me to do something spectacular, and that’s when I start to feel a bit self-conscious. I have no idea what sorts of entertainment a cow would enjoy. Sometimes I moo at them just to see what they’ll do, which is usually nothing. Sometimes they moo back though and then I wonder exactly what was it I said. Where’s Dr. Dolittle when you need him?

The curious cows at the Yellow Quill Prairie Preserve like to stare at me.

I’ve also been looked over quite thoroughly by the resident Upland Sandpiper. Usually it just chatters at me but last week it flew over a couple times and then landed in the grass and started walking in a circle around my plot for a couple of minutes. It kept peeking out from behind the grass like it thought I was up to no good. Although I would have loved to get a good picture of it, it was just too sneaky and all I got was photo of it as it flew away.

This Upland Sandpiper kept stalking me!

Mammals and birds aren’t the only wary creatures at the preserve. A beautiful Tiger Swallowtail (Papilio glaucus) was there, feeding on the Purple Locoweed (Oxytropis lambertii) but, like most butterflies, it did not want me to take its' picture. Neither did a Hummingbird Clearwing Moth (Hemaris sp.). Those insects are so fast (like a hummingbird) that they are almost impossible to photograph. I did get one very blurry shot in before I could adjust my camera to “action mode” but by then it was gone. Maybe one day I’ll manage to take a decent photo of one.

This jittery Tiger Swallowtail (Papilio glaucus), seen here feeding on a Purple Locoweed (Oxytropis lambertii), was not very photogenic.

In general, insects that have no form of self-defence, like butterflies and moths, are less apt to let you get anywhere near them. Or maybe they think they’re just too sexy for my camera. The jitteriness of butterflies has likely resulted in a flaw in my field data: I don’t know a lot about what they are feeding on, or how frequently they do so, due to their reluctance to approach me. I try to stay as still as possible, but I suspect that my butterfly and moth observations are low for this reason. Maybe I should start wearing camouflage.

I just managed to snap a blurry picture of this Hummingbird Clearwing Moth (Hemaris sp.) on Purple Locoweed (Oxytropis lambertii) before it zoomed away.

The presence of all these suspicious animals is why my favorite animals on the prairies are the bumblebees (Bombus spp.). Bumblebees are so confident that you are not going to hurt them (due to their stingers) that they’ll let you stick a camera right in their face! As a result I have a plethora of bumblebee images and some really great visitation data. Yeah bumblebees!

A Bumblebee (Bombus sp.), seen feeding here on a Gaillardia (Gaillardia aristata) flower, is just too busy to care if you take its picture.

 

06/01/17

Spring has sprung

Once again I am studying pollinators at the Nature Conservancy’s Yellow Quill Prairie Preserve (http://www.natureconservancy.ca/en/where-we-work/manitoba/featured-projects/yellow_quill_prairie.html) just south of Canadian Forces Base Shilo. Last year I made the mistake of starting my field surveys too late and missed the blooming of a number of early flowering plants like prairie crocus (Anemone patens), three-flowered avens (Geum triflorum) and chickweed (Cerastium arvense). This year I did my first survey on May 11, which was already almost too late for the crocuses but just in time for the others.

Prairie crocus (Anemone patens) finished flowering in early May.

Spring is not the busiest time on the prairies as bee populations are not at their peak yet. However, it is a very important time because the queen bees start feeding. Bee queens are the only ones that survive the winter, going into hibernation in the soil. In spring, the hungry queens begin feeding on both pollen and nectar from the early blooming wildflowers. Once they have fattened up a bit, they select appropriate nesting sites and lay the eggs that will produce the first worker bees. Some queen bees brood their eggs, keeping them warm until they hatch. The workers typically start showing up in June.

Queen bumblebees often feed on three-flowered avens (Geum triflorum).

My task this May was to find out what the queens were feeding on. Bumblebees (Bombus spp.) were most fond of three-flowered avens with 61% of all visits being to that species followed by chickweed (25%). Andrenid bees (Andrena spp.), on the other hand, preferred the chickweed visiting it 95% of the time. The little sweat bees (Lasioglossum spp.) weren’t terribly abundant yet but only visited the chickweed. In fact, one day it was so windy that I didn’t see any sweat bees at all. If they had ventured out, they would have been incapable of flying without getting completely blown off course as the wind speed was almost 50 km/hour. The few big insects that were out (e.g. bumblebees, clearwing moths) were zooming past me very quickly, if they were going in the direction of the wind that is.

Streaks of pink and white at Yellow Quill Prairie represent three-flowered avens (Geum triflorum) and chickweed (Ceratium arvense) flowers in abundance.

Interestingly, I also saw domesticated honeybees (Apis mellifera), visiting three-flowered avens and chickweed in equal amounts. These honeybees are being kept by one of the nearby farmers and, since there are no crops in flower yet, they were out searching for something to eat. To me, this clearly demonstrates the value of prairie preserves. Although some consider wild prairies to be “waste land” because they aren’t being used to grow crops, they do provide us with benefits: they help pollinating insects survive and reproduce, are a safe place for nesting, and are a source of honey for us to eat.

Happily, except for the strong wind that one day, the weather was great during my surveys: sunny and warm. Hopefully my luck will hold out and I’ll have clear skies for my next field trip in early June.

05/18/17

Make Goldenrods Great Again!

This is a blog about pollination. It’s gonna be great! You’ll love it. I write the best blogs. There’s this one plant—it’s a Goldenrod—it is THE best plant for pollinators. Manitoba has THE best plants for pollinators. Not like Ontario. All the pollinators love Goldenrod: bees, flies, butterflies, moths—even beetles. All the other plants in the prairie—losers. Can’t attract the pollinators! Can’t do it! But that Goldenrod! So many pollinators visit it that there’s this bug—it’s an ambush bug—that it sits on the Goldenrod and eats the pollinators that show up. It eats them! Totally devours them! Nothing left but a pathetic husk. Sad.

Ambush bug eating a pollinator!

Goldenrods are the best. They used to be all over the place. Then immigrants came, cut down all the Goldenrods and started growing plants from Eurasia. Like wheat. Pollinators don’t like wheat! They hate it! There’s no nectar! None! Now the native pollinators, they don’t have anything to eat! Nothing! That’s why we should grow Goldenrods. A lot of them. So many that it will look like a wall. A big, golden wall. It’s gonna be beautiful! The pollinators will love it.

04/12/17

More about Mycorrhizae

Have you ever seen an uprooted tree while walking in a forest? If so, you might have noticed strands of white thread-like structures attached to the tree roots and running through the soil. What you were seeing were mycorrhizal fungi. These fungi surround and bind almost all of the plants growing in an ecosystem together. Some of them, like the honey fungus (Armillaria mellea) are even luminous, glowing in the dark. The honey fungus is also the world's largest organism (that we know of, at least); one specimen stretches for an astounding 2.4 miles (3.8 km) (Ferguson et al. 2003)! This fungus is attached to hundreds of trees, which are also attached to countless other mycorrhizal fungi and forest plants. Sugars, water and nutrients are exchanged between the plants and the fungi. Trillions of insects and microorganisms live on, and interact with these fungi-root systems. Unfortunately, our understanding of this massive system is horrible, because we can’t actually see what is going on.
It’s important to remember that the parts of a forest or a prairie that we can see above ground are probably less than a half of the ecosystem’s total biomass; almost all of the fungal biomass is beneath the ground.

One of the world's largest organisms is a honey fungus (Armillaria mellea). From Wikimedia Commons

Some mycorrhizal fungi appear to only associate with certain plant species while others are less discriminating. About 80% of all plant species (including all trees) associate with mycorrhizae; the plants that don’t are the rushes, sedges, nettles, mustards, goosefoots and pinks. Some plants are so dependent on mycorrhizae that they can’t live without them: the orchids are one such group. While most mycorrhizal relationships appear to be mutualistic, with both partners benefiting from the interaction, many orchids appear to be parasitic on the fungi!

Plants in the mustard family like Western wallflower (Erysimum asperum) are some of the only species that do not associate with mycorrhiza.

Plants in the mustard family like Western wallflower (Erysimum asperum) are some of the only species that do not associate with mycorrhiza. © MM

The most parasitic orchids are the coralroots (Corallorrhiza spp.). These species are vascular plants that can no longer photosynthesize, as indicated by the fact that they are orange instead of green. Coralroot orchids parasitize mycorrhizal fungi, which form relationships with pine (Pinus spp.) trees. Thus all of the sugars the coralroot uses to fuel its growth come from the pine trees (via the mycorrhiza), and the water and minerals it needs come from the fungus (Zelmer and Smith 1995).

Striped coralroot (Corallorrhiza striata) parasitize both trees and mycorrhizal fungi. © MM

Mycorrhizae appear to help tree “parents” feed their offspring. In “The Hidden Life of Trees” the German forester Peter Wohlleben describes how sugars produced by large, adult trees in a forest are transferred through the mycorrhizae to the saplings, which are unable to access much light. In this way, young trees are provided with enough nourishment to stay alive until the adult tree dies and the young ones can obtain light for themselves. Resources are even transferred between trees of different species. Douglas firs (Pseudotsuga menziesii) were found to transfer nutrients to paper birch (Betula papyrifera) trees in the spring and fall when the birches had no leaves and the birches transferred nutrients to the firs in the summer when their leaves were shaded (Song et al. 2015). Wohllenben thinks that this happens because “a tree can be only as strong as the forest that surrounds it.”

Paper birch (Betula papyrifera) trees exchange nutrients with other trees through mycorrhizal links. © MM

This is just the tiniest shred of what scientists know about mycorrhizae and new studies are being conducted all the time using new tools and analytical techniques. Next time you're out hiking in a forest remember this amazing invisible world under your feet!

(more…)

03/06/17

Mycorrhizal Mushrooms

Have you ever wondered why the only fresh mushrooms you can get in stores are button, cremini and portabello (all different varieties and stages of Agaricus bisporus)? Or why the fancy mushrooms, like morels (Morchella spp.) and chanterelles (Cantharellus spp.) are generally only available dried? And why are those dried mushrooms so expensive anyway? Can’t they just plant them in a field like wheat? To understand the answer to these questions, you need to know a few things about what mushrooms really are.

Morels are much loved edible, wild mushrooms.

Morels (Morchella sp.) are much loved edible, wild mushrooms. (c) MM

A long time ago scientists classified all organisms as either “plants” or “animals” largely based on whether they had a means of locomotion. For this reason, mushrooms (a.k.a. fungi), were classified as “plants”. Soon, however, scientists began to realize that fungi were not actually like plants at all: they produced spores instead of seeds, and most importantly, they weren’t green. Turns out fungi don’t produce their own food like plants do; they need to “eat” plants or animals-either living or deceased. In this way, they are actually more like animals.

Some fungi are parasites on plants, animals, protists or other fungi. You may be familiar with fungal crop parasites like corn smut (Ustilago maydis), rusts (e.g. Puccinia spp.), powdery mildew (e.g. Podosphaera spp.), ergot (Claviceps purpurea) or the infamous potato blight (Phytophthora infestans). In fact, some parasitic fungi even feed on people. Ever had jock itch (Tinea cruris), athlete’s foot (Tinea pedis) or a “yeast” (Candida albicans) infection? If so, a fungus was feeding on you. Gross!

Corn smut (Ustilago sp.) is a fungal parasite on corn plants. From Wikimedia Commons.

Corn smut (Ustilago sp.) is a fungal parasite on corn plants. From Wikimedia Commons.

Other fungi are what scientists call “saprophytes”. These are fungi that eat dead plants and animals, not living ones. The fresh mushrooms that you get in grocery stores have this habit. Mushroom farmers collect various crop residues or composted manure to “feed” their fungal colonies. The main body of the fungus, called “mycelium”, consists of thin root-like structures called “hyphae”. These hyphae grow through the compost, feeding on the nutrients. When certain hyphae meet at the right time they begin to form a reproductive structure, which is the “mushroom”. The purpose of the mushroom is to produce and release spores (which are similar to seeds) to colonize new habitats.

Shiitake (Lentinula edodes) mushrooms are also commercially grown, albeit in a different way than button mushrooms: they grow on rotting hardwood trees, like oaks (Quercus spp.) instead of compost. This is why shiitatkes have a woody flavour to them. Oyster mushrooms (Pleurotus ostreatus) are similar to shiitakes, growing on various deciduous trees, often poplar (Populus spp.). You can actually buy special kits to help you grow your own shiitake and oyster mushrooms!

Oyster mushrooms (Pleurotus ostreatus) taste a bit wood because they grow on wood!

Oyster mushrooms (Pleurotus ostreatus) taste a bit woody because they grow on wood! (c) MM

However, some fungi are what botanists call “mycorrhizal”, literally Latin for “fungus root”. Mycorrhizal fungi form symbiotic associations with various wild plants, often trees. The hyphae wrap around plants’ roots and absorb some of the sugar that the plant produces via photosynthesis. In exchange, the fungus provides the tree with water and hard to get nutrients like phosphorus. So ultimately the relationship seems to be beneficial to both parties. Many of the wild mushrooms that we love are mycorrhizal and associated with conifers like pine (Pinus spp.): pine mushrooms (aka Matsutake) (Tricholoma matsutake), delicious milkcaps (Lactarius deliciosus) and porcinis (Boletus edulis). Chanterelles are associated with several species of conifers and deciduous trees. Truffles (Tuber spp.), on the other hand, prefer deciduous trees like oaks (Quercus spp.) and hazelnuts (Corylus spp.). Some morels (Morchella spp.) will grow on decaying organic matter like the button mushrooms but other species are mycorrhizal.

Delicious milkcaps (Lactarius deliciosus) are mycorrhizal associates of pine trees.

Delicious milkcaps (Lactarius deliciosus) are mycorrhizal associates of pine trees. (c) MM

So any attempt to cultivate these species would require growing a forest of appropriate tree hosts, inoculating the soil and hoping that they will eventually produce mushrooms. Although this sounds simple, there are many mysterious things going on in the soil that we barely understand and the factors that trigger mushroom production are one of them. In my next blog, I will be exploring some of the fascinating relationships between mycorrhizal fungi and Manitoba’s wild plants.

Dr. Diana Robson

Curator of Botany

See Full Biography

Dr. Robson obtained a Master's Degree in Plant Ecology and a Ph.D. in Soil Science at the University of Saskatchewan. She has been working at the Manitoba Museum since 2003, conducting research mainly on rare plant and pollination ecology.