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Blog

Botany

Botany

09/14/21

Hot to Trot: Plant Hunting in a Drought

Doing biological field work always comes with challenges. Since I began working at the Museum in 2003, the summers have been relatively wet. As a result, I’ve had to deal with muddy roads, many, many biting insects thirsty for my blood, and bootfuls of water obtained while exploring flooded wetlands. This year though, the roads were good, the biting insects non-existent, and many wetlands were so dry that I could walk right into the middle of them-no rubber boots required! In contrast, my main concern this year was possibly getting heat stroke!

This wetland near Lac du Bonnet that I visited was almost completely dry.

As part of my research for a new book on Manitoba’s flora, I’ve been trying to track down populations of historically-collected plants (some of which haven’t been collected for over 100 years) to see if they still grow here. Fortunately, this year, all of the sites I needed to visit were close to major bodies of water: Lake of the Woods, Lakes Winnipeg and Manitoba, and Lac du Bonnet. As a result, I was able to go for a quick swim in the nearby body of water to cool off after a long day of hiking. Swimming is especially satisfying when you have been wearing long pants, wool socks and hiking boots in 30°C+ temperatures all day. Field work this year also involved drinking copious amounts of water (which were nearly completely sweated out given that I didn’t have to go to the bathroom all day!), lots of SPF 50 sunscreen, taking breaks under the shade of a tree, and wearing a cooling, water-soaked bandana around my neck.

Dipping my hot feet in the cool lake water at Elk Island Provincial Park felt amazing!

I also got lucky with my field work, finding a new rare plant population and a new plant species for the province. The first rare plant species I discovered was Hairy Bugseed (Corispermum villosum). This species is currently ranked S1 (critically imperilled) in Manitoba because there are only three populations known in the province. I discovered a small population at St. Ambroise Beach Provincial Park on Lake Manitoba. Additionally, the population of this species that occurs out at Lake Winnipeg was found to be more extensive, extending all the way to Elk Island Provincial Park.

A new population of Hairy Bugseed was discovered at St. Ambroise Beach Provincial Park.

Out at Lake of the Woods, there are several plant species that reach the northeastern edge of their range. One is the lovely Small Purple Fringed-orchid (Platanthera psycodes). It was suspected to occur in Manitoba, but no one had actually collected a specimen until 1984. As I had never seen it before, I was thrilled to find and photograph the two plants in flower at the site.

The Small Purple Fringed Orchid was an exciting, and beautiful find!

Not far from the orchid, I saw another plant that I was on the lookout for: White Avens (Geum canadense). Although this species is relatively common in Ontario, Quebec, New Brunswick and Nova Scotia, it has apparently never been collected in Manitoba before. I carefully removed part of the stem only (not the root) to make an herbarium specimen, after verifying that there were more than ten additional plants in the vicinity.

I collected the first ever specimen of White Avens in Manitoba this summer.

Finding these new, rare plant populations made the hot, July temperatures much easier to handle. The specimens collected will be carefully preserved in perpetuity at the Museum to document these plant populations for conservation purposes, and for future researchers to study.

08/18/21

The Importance of Being a Flower

Like many of you, I enjoy walking through my neighbourhood and smelling the sweet fragrances of the summer flowers. Unfortunately, like many things, flowers are ephemeral. When I see a flower, I am always reminded of the Robert Herrick poem urging us to:
“Gather ye rosebuds while ye may,
Old Time is still a-flying;
And this same flower that smiles today,
Tomorrow will be dying.”

A new, temporary exhibit on seeds is in the Museum’s foyer.

(more…)

05/12/21

Travelling Plants of the Prairies

Plants and fungi were challenging organisms to include in our new Prairies Gallery because most of our 50,000+ Museum specimens are preserved in a flattened, dehydrated condition. Not very attractive! Further, because these organisms don’t move the way animals do, people don’t seem to find them interesting. But are they really the passive, immobile creatures that we think they are? Our new exhibit case called Travelling Plants and Flying Fungi, attempts to dispel this notion.

Most Museum specimens are dried and flattened, like this Stiff Goldenrod (Solidago rigida) plant.

The fact of the matter is, plants and fungi need to be able to move, otherwise they would never have colonized land! However, it is not the adults that do the actual moving; it is their gametes (pollen) and offspring (seeds). Before a plant can make seeds, it has to have its eggs fertilized by pollen grains from another plant. Since a plant can’t just get up and walk to another plant to give it some pollen, they have to use wind or animals, called pollinators, as couriers. To depict this process, the new Museum case includes intricate 3-D models of a wind-pollinated grass and four animal-pollinated flowers, as well as their pollinators, instead of flattened plants.

Before the final graphics were chosen, the layout of the case needed to be tested.

The plant models were created by the Museum’s talented Diorama & Collections Technician. Two of the models are real plants that were “mummified”, and then painted to look alive. The other three are entirely artificial. To make them, a plant was collected, and then molds made of the parts. These molds were used to create fake leaves, stems, flowers and fruits, which were then assembled together and painted.

The Golden Alexanders (Zizia aurea) model has two pollinators on it: a beetle and a butterfly.

Once a plant is pollinated, seeds, protected inside fruits, develop. Seeds also need to disperse, and, once again, wind and animals are the couriers. To illustrate the different methods of dispersal, various seeds and fruits from the Museum’s collection were selected for display.

Inset cases display various kinds of fruits and seeds. These species have hooked burs that catch onto animal fur.

Some plants, fungi and lichens do not produce multi-celled seeds; they produce tiny, single-celled structures called spores. Since they are so small, they typically disperse very well in the wind. Specimens of several common prairie spore-producers, including fungi and club-moss, are displayed in between the plant models.

Puffball fungi (Calvatia spp.) were collected, and quickly dehydrated, for this new display case.

Manitoba prairies have many fascinating plants, fungi and lichens in them. How they survive and reproduce is now one of the stories we tell in the Museum. My only regret is that we couldn’t include more species in the gallery. Hopefully, this new case will inspire our visitors to spend more time paying attention to, and appreciating, the plants in our wild prairies.

04/20/21

What’s that stuff on my tree? A guide to Manitoba’s lichens

If you’re an observant person, you may have noticed colourful things growing on Manitoba’s trees and rocks. Although some of these organisms are mosses (especially near the base), they are more likely to be lichens.  Bright orange Firedot Lichens (Caloplaca spp.) are common on Manitoba’s elm and oak trees.

Lichens are symbiotic organisms; they consist of a fungus (called a mycobiont) and an alga (called a photobiont). In some lichens there is also a cyanobacteria or a second or third species of algae (there are still a lot of unknowns when it comes to lichens). The common dog lichens (Peltigera spp.) typically have cyanobacteria in them, often from the genus Nostoc, a free-living species that looks like bits of crumbled tar when dry. The algae and cyanobacteria, if present, photosynthesize, producing sugar, which they share with the fungus. The fungus absorbs water and dissolved minerals directly from the environment (so it doesn’t need any roots), and shares it with the other species. Cyanobacteria can also take nitrogen gas from the air, turn it into a chemical form, and share it with the other partners.

Dog lichens (Peltigera spp.) are common on moist, forest floors.

Lichens grow in the patterns they do to maximize the amount of light they intercept; some species look like tree branches (called fruticose = branch-like lichens) for this reason. Other lichens are leaf-like (i.e. foliose), or crusty (i.e. crustose). Some lichens living in really harsh environments (like the Antarctic) are cryptoendoliths, meaning that they live inside the rock, penetrating the tiny spaces in between rock crystals.

Crustose lichens grow on rock outcrops in places like Whiteshell Provincial Park.

In the prairies, lichens often grow in hot, sunny habitats, such as sandy soils, and on glacially-deposited rocks. They are also common on fenceposts and abandoned human artifacts, like collapsing homesteads and rusty ploughs. In forested areas, lichens are common, growing on trees, as well as mossy, forest floors. In the Canadian Shield, rock outcrops are often almost completely covered by lichens. In urban areas, lichens are sometimes found on old buildings, like the legislature. Different species grow on these different substrates (hardwood vs. softwood, sandy soil vs. clayey soil, granite vs. limestone) so make sure you record this information when trying to identify lichens.

In the prairies, Reindeer Lichens (Cladina spp.) often grow along with Creeping Juniper (Juniperus horizontalis) on dry, sandy soils.

Since they don’t need soil, lichens are some of the first organisms that begin growing after large disasters wipe out all vegetation in an area. They are often the first to arrive after hot fires or mining activity (such as sand, gravel and coal mining). Acids in the lichens break down rocks, contributing to soil formation. Lichens can completely desiccate when it is dry, growing again when it rains. Due to this periodic desiccation, lichens tend to grow very slowly, reaching extremely old ages. Some lichens can be aged the way trees are: by counting their growth rings. Some lichens (i.e. yellow-green map lichens) have been dated as being over 8,600 years old.

Lichens are often the first organisms to start growing on disturbed soils.

Lichens reproduce themselves vegetatively, by breaking off into tiny pieces, and both sexually and asexually. Sexual fruiting bodies of various kinds (e.g. pycnidia, asci, apothecia etc.) are produced by the fungus. They release small, single-celled spores which germinate into new, partner-less fungi. These tiny fungi must find free-living alga to become lichens again. To allow both the fungus and the algae to disperse together, lichens also produce asexual propagules, usually at the branch tips, of various kinds (e.g. soredia, isidia, pycnidia etc.). These tiny clusters of cells, once dispersed, often by wind, will grow into a new lichen.

A few of the most common lichens in southern Manitoba are described below:

Pebbled Pixie-cup Lichen (Cladonia pyxidata)

Pixie-cup lichens were so named because ancient Europeans thought that fairies or
pixies would use these structures as goblets to drink from. The “cups” are actually the reproductive structures of the lichen. This species found in all provinces, occurring on forest floors and sometimes tree bark.

Pebbled Pixie-cup Lichen (Cladonia pyxidata)

Reindeer lichen (Cladina mitis)

As the name implies, this species is eaten by “reindeer”, called caribou here in Canada. Reindeer lichen are common in the arctic and boreal forest, but are also found farther south. In Manitoba’s prairies, it is most common on sandy soils. This fruticose lichen grows sexual and asexual structures at the very tips of the branches. Vegetative reproduction via fragmentation is also a common method of spreading, as the branches are fragile when dry.

Reindeer lichen (Cladina mitis). L-657

Sand-loving Iceland Lichen (Cetraria arenaria)

Like the reindeer lichen, this species is found on sandy or thin soils in the prairies. However, it is a prairie specialist, not found farther north. You can find it on the sand dunes near Portage la Prairie, Oak Lake and Carberry. It is a fruticose lichen with some flattish portions and upturned, spiny margins. This species reproduces mainly vegetatively via fragmentation or the production of asexual propagules. Sexual reproduction is infrequent, with the spore-producing structures (i.e. apothecia) located at the tips.

Sand-loving Iceland Lichen (Cetraria arenaria)

Rosette Lichen (Physcia spp.)

Species in this genus grow on alkaline substrates, such as calcareous, siliceous and basaltic rocks, bones, bark and soil. They often grow on substrates that are high in calcium, nitrogen and phosphorus, such as places where birds like to stand and poop. For the aforementioned reason, they have been called ornithocoprophiles (i.e. bird-poop lovers). They are foliose lichens that grow in a rosette. They mainly produce asexual soredia on their upper surfaces.

Rosette Lichen (Physcia spp.). L-664

More lichen information can be found in this nifty little booklet available on-line (https://www.muskokawatershed.org/wp-content/uploads/LichenID.pdf) but if you are really serious about lichens I recommend investing in Irwin Brodo’s Lichens of North America.

03/03/21

Welcome to a New Gallery!

When the Museum opens to the public again, our visitors will be in for a pleasant surprise. The very first of our nine galleries, now called the Welcome Gallery, has been completely renovated. The much-loved Bison diorama is still there, but the exhibits surrounding it are all different. Originally built in the 1970’s, this gallery definitely had a dated vibe to it that needed to change. Further, it was no longer doing its job as an effective introduction to the province of Manitoba or to the Museum’s galleries.

The welcome wall introduces visitors to both the province, and the Manitoba Museum.

The role that First Nations, Inuit and Métis peoples played in the settling and formation of the province of Manitoba is now described in several places in the renovated gallery, including a beautiful new exhibit on treaties. This exhibit was created in cooperation with the Treaty Relations Commission of Manitoba, and features the medals, pipes and pipe bags associated with these agreements. It demonstrates the fact that the Museum is committed to working with Indigenous peoples to accurately tell the history of Manitoba.

A beautiful, new treaty exhibit was set up to the left of the iconic Bison Diorama.

Another prominent component of the gallery is a new wall projection depicting 18,000 years of Manitoba history in two minutes! The Museum’s seven Curators all worked together on this video, which portrays, among other things, melting of ice age glaciers, changes in vegetational communities (i.e. biomes) over time, migration of Indigenous peoples into Manitoba, migration of settlers after confederation with Canada in 1870, and predicted future temperatures due to climate change.

Curators pulled out many candidate specimens and artifacts when deciding what to put in the new gallery introduction case.

The most eye-catching new exhibit is the gallery introduction case. The theme of each of the Museum’s remaining eight galleries are revealed through the iconic objects–animals, plants, fossils, minerals and artifacts–on display. Some galleries feature human history stories such as the fur trade in the Hudson’s Bay Company Collection Gallery, but four galleries are about Manitoba’s biomes (e.g. Arctic & Subarctic, Boreal Forest, Parklands and Prairies), and feature both natural and human history exhibits. Curators looked deep into the Museum collections to find some of our most intriguing objects to display. Unique colours and icons on the banners associated with each gallery are repeated at their entrances in the Museum, to let people know where they are, and what they will be seeing.

A new case describes each gallery, including the Prairies Gallery, and displays iconic specimens like little bluestem grass, and artifacts from the Museum’s collection.

As a scientist, I was disheartened that the old Orientation Gallery did not highlight the fact that this Museum has scientific collections and does research. The new Welcome Gallery does a better job of explaining this, allowing us to display and depict some of Manitoba’s fascinating wildlife. In particular, the new Discovery Room exhibit, The Museum’s Collection Illuminated: Celebrating 50 Years, highlights specimens and artifacts collected by, or donated to, the Museum. A slide show gives visitors a peak into the lives of the Curators and Collections staff that brought this new gallery to life.

This giant puffball fungus, donated to the Museum many years ago, is now on display in the Discovery Room.

As the lead Curator for the Welcome Gallery renewal, I am thrilled with the look of this space! I hope our visitors will enjoy seeing what we have been busy making during the pandemic.

New introductory panels are now located at the entrance to each gallery to help our visitors know where they are.

01/07/21

Anchoring the Earth

One of the most impressive plant specimens at the Manitoba Museum is a huge, preserved grass that shows the entire root system. I think the reason everybody likes this specimen is that it provides a perspective that no one ever has: what a plant actually looks like under the ground. There was just one problem with that grass: it’s not actually a native species. It’s a Eurasian species called Crested Wheatgrass (Agropyron cristatum) that was brought to Canada and widely planted in the 1930’s. During our planning for the new Prairies Gallery, the Curators strongly felt that visitors needed to see native species of plants when first entering the gallery. The process to collect plants for this exhibit was previously described in “I once caught a plant that was this big”.

The June Grass specimen being excavated.

In addition to the tap-rooted White Prairie-clover (Dalea candida), the display case includes a specimen of Manitoba’s Provincial grass, Big Bluestem (Andropogon gerardi) and a June Grass (Koeleria macrantha). White Prairie-clover relies heavily on associated microbial organisms to obtain adequate nutrition; mycorrhizal fungi help it obtain water and minerals like phosphorus, while nitrogen-fixing bacteria help it obtain nitrogen. This means that the roots of prairie-clover do not have to be very extensive, as they mainly serve as attachment points for its associated organisms. Big Bluestem is a warm season grass that flowers in late summer when the soil is relatively dry; this is why its root system is so extensive and deep. In contrast, the June Grass is a cool-season species that flowers in June when the soil is still fairly moist; the shallow, densely hairy roots are able to obtain all the resources the plant needs. Thus, this exhibit nicely illustrates the main strategies that plants use to exploit different niches in the soil both in space and time.

Debbie Thompson, installing the White Prairie-clover specimen.

After collecting these plants, the preservation process was out of my hands. Our talented Diorama and Collections Technician, Debbie Thompson, soaked the plants in a preservative for months, then carefully untangled the roots, painted the stems and roots to the correct colour, created false petals and came up with a clever mounting technique along with Bert Valentin, one of our productions staff. For a proper backdrop to the plants, I obtained an image of the correct soil profile from the Manitoba Soil Science Society, a Stockton Loamy Sand.

Last month, the exhibit case and graphics were installed, and our plants were ready to move into their new home. It was an exciting day to see my vision come to life. I hope you all enjoy being greeted by some new plants as you enter the gallery.

Debbie Thompson (left) and a very proud Curator: me!

If you are wondering what happened to that Crested Wheatgrass specimen, it has been relocated to the second half of the gallery, which tells the story of Manitoba’s post-European contact history. It is now located next to a history case on the impact of the Great Depression on Manitobans, correctly interpreted as a species planted in the 1930’s to help stabilize soils that were blowing away due to the drought.

The exhibit case and associated interpretive panel.

12/07/20

Popping Pine Cones and Other Fun Facts About Conifers

I recently read that, thanks to Covid-19, there’s been a run on Christmas trees because so many people are staying home for the holidays this year. In a world that suffers from plant blindness (i.e. an inability to see the trees for the forest), “Christmas trees”, are among the most well-known “species” of plant. Except that “Christmas tree” is not actually A species; it is ANY kind of coniferous (i.e. cone-bearing), evergreen tree that we decorate. So, if you don’t know much about conifers, here are 10 fun facts about these common trees many of us share our homes with once a year.

1. Many different species are used as Christmas trees.
Some of the most popular Christmas tree species in Manitoba are native ones: Eastern White Pine (Pinus strobus), White Spruce (Picea glauca) and Balsam Fir (Abies balsamea). Other species are non-native, most commonly Fraser Fir (Abies fraseri) and Scots Pine (Pinus sylvestris). How to tell them apart? Just remember this little rhyme about the needles of these trees: firs are flat, spruces are stiff, and pines are in pairs.

Balsam Fir is a popular Christmas tree because the needles are not shed as quickly as in spruce trees.

2. Not all conifers are evergreens and not all evergreens are conifers.
The term evergreen just means that the plants’ do not shed all of their leaves in autumn the way deciduous plants do. Being evergreen is advantageous for plants that grow in cold, nutrient-poor soils where organic matter decomposes slowly (i.e. pretty much all of Canada!). Most conifers are evergreens, but Tamarack (Larix laricina) trees are deciduous. Tamaracks can afford to regrow new needles each year because they can reabsorb many of the minerals in them before they turn yellow and fall off. Some flowering plants in nutrient-poor habitats, like Bearberry (Arctostaphylos uva-ursi), are evergreen, with thick, but broad (not needle-like) leaves that stay on all winter.

Bearberry, shown here growing over a rock, is an evergreen shrub that produces white, bell-shaped flowers and red fruits, not cones.

3. In conifers, the females are on top.
Manitoba’s conifers are not like people: they don’t have different genders. Conifers produce both male cones, which produce sperm, and female cones, which produce eggs. The male cones are typically produced on the lower branches and the female cones on the top ones. This positioning helps to prevent self-fertilization because the sperm-containing pollen won’t fall on the trees’ own female cones.

4. Manitoba has popping pines.
To protect Jack Pine (Pinus banksiana) seeds from predators like squirrels and birds, their cones are tough and tightly closed (i.e. serotinous). The cones will not open, sometimes for decades, until they are exposed to intense heat, such as that from a forest fire. In fact, shortly after a forest fire, you can hear the sound of Jack Pine cones popping open and releasing their seeds. You can hear this sound too, if you collect closed cones and put them near a bonfire or on top of a radiator.

Jack Pine is a conifer that has adapted to the natural forest fires that periodically occur due to lightning strikes.

5. Conifers can fly.
The seeds of most conifers have a thin “wing” attached to them. These wings help the seeds, which are near the top of the tree, glide some distance away, so that the baby trees do not have to grow in the shade of their parent. Juniper (Juniperus spp.) and yew (Taxus spp.) seeds are contained in fleshy cones (incorrectly called “berries”), which are eaten by birds. Thus, they can also fly, although they will be in the stomach of a bird when they do. Fortunately, the seeds are usually not digested, just the fleshy part. They are usually excreted intact in the birds’ dung.

6. Conifers are always in your house (or ARE your house).
Unless you have a bidet, don’t use any paper products at all, and live in a house made entirely of straw, you have conifers in your house all the time. Paper products like toilet and wall paper, paper towel, newsprint, cardboard and printing paper are all made, at least in part, with “softwood” trees, which are conifers. As well, much of the timber we use to build our houses and furniture comes from conifer trees like pine and spruce. If you eat pesto sauce or drink gin, you are also consuming conifers. Pesto sauce is typically made with pine nuts, and gin is usually flavoured with juniper cones.

7. A conifer is Manitoba’s provincial tree.
Manitoba’s provincial tree is White Spruce (Picea glauca). This is the dominant conifer in North America, growing in every Canadian Province. Their life span is relatively short, about 250-300 years old, in part because spruce forests become more susceptible to wildfires as they age. White Spruce provides much of the habitat for migratory songbirds and small boreal mammals, which eat the insects that live on them, or the seeds of their cones. Crossbills (Loxia spp.) and squirrels are busy eating White Spruce seeds right now, even here in the city.

White Spruce trees grow in upland areas all over Canada’s boreal forests.

8. Conifers are the oldest trees.
The Great Basin Bristlecone Pine (Pinus longaeva) is the worlds’ longest-lived, non-clonal tree species, typically surviving for thousands of years. The oldest individual of this species, found in California, was estimated to be just over 5,000 years old, so it germinated several hundred years before the Egyptians built the first pyramid.

The oldest trees in the world, Great Basin Bristlecone Pines, look just as you would expect an ancient tree to look: gnarled and knotty. From Wikimedia Commons.

9. Conifers are the biggest trees.
A tree named “General Sherman” is the largest tree in the world at 1,487 cubic metres. It is almost 84 metres tall, about the height of a 26-story building, and has a 31-metre circumference at ground level. It is a species of Giant Sequoia (Sequiadendron giganteum), and can be found in Sequoia National Park in California. They make bad Christmas trees, cause who could ever get the star on top?

A Giant Sequoia with people at the base for scale. From Wikimedia Commons.

10. Dinosaurs ate conifers.
Conifers are the oldest seed plants; they evolved about 300 million years ago in the Carboniferous Period. Unlike the earliest land plants, which still needed water to reproduce, conifers did not: their sperm became contained in pollen grains, which could be transported to other plants by the wind instead of water. This enabled conifers to live in relatively dry areas. They became the dominant plants during the “Age of Dinosaurs”: the Triassic, Jurassic and Cretaceous Periods. So, any plant-eating dinosaurs would probably have eaten conifers. Fortunately, dinosaurs are extinct so they will not eat your Christmas tree.

Wanting more conifer trivia?  Check out this post from the past to learn why people drank conifer “beer”: https://manitobamuseum.ca/drinking-christmas-trees-that-is/

Enjoy a tree-filled holiday!

 

10/21/20

The Dirt on Soil

Soil is sometimes called “dirt”, as if it is something completely devoid of value. But without healthy soil, there would be no food, and without food, humans are doomed. We owe this thin layer of life, a respect far exceeding what we typically show it.

Soil consists, not just of sand, silt and clay, but organic matter from plants, fungi and animals, as well as a diverse community of soil organisms, living in complex communities that we barely understand. Soil organisms play a crucial role in the persistence of life as we know it, and they are unfathomably abundant: there are more microorganisms in a teaspoon of soil than there are humans on earth. Most importantly, soil organisms help decompose dead organic matter, so that the nutrients in them can be used by living creatures. If this recycling did not happen, all life on land would eventually screech to a halt.

Sunflowers (Helianthus annuus) that can associate with soil fungi (i.e. mycorrhiza), are more drought-tolerant, and yield more seeds. © The Manitoba Museum.

Most people are familiar with above-ground food pyramids: producers (e.g. grass) are eaten by herbivores (e.g. bison), which in turn are eaten by predators (e.g. wolves). What many don’t know is that this same structure also occurs in underground ecosystems. Life in the soil is kind of like the upside-down in the TV show Stranger Things; the same but different, and much darker.

Plants are the producers in the soil, transferring sugar formed by photosynthesis in their leaves to their root systems. Both dead and living roots, and root exudates (i.e. chemicals that leak out of the roots) are consumed by small plant-eaters (i.e. herbivores) like bacteria, fungi, mites and roundworms (i.e. nematodes), as well as larger animals like mice, gophers and voles. These herbivores are eaten by predators (i.e. carnivores) of various sizes. Small predators include protozoans, carnivorous roundworms and mites, springtails, ants, spiders, sowbugs, centipedes, millipedes, beetles and earthworms. These small predators may in turn be eaten by larger subterranean predators (i.e. secondary carnivores) like moles and shrews, as well as larger creatures above the ground, like birds and mammals (e.g. coyotes).

Four out of five animals on earth are nematodes or roundworms. This species, Criconomella sp. is a native, root-feeding nematode. © Raf Otfinowski and Victory Coffey.

But it is not just a mite-eats-nematode world: the soil also contains organisms that partner with each other in mutually beneficial relationships: nitrogen-fixing bacteria and mycorrhizal fungi form associations with plant roots that help both species thrive. Soil bacteria and fungi may also help plants by detoxifying harmful chemicals, like pesticides, in the soil.

Nitrogen-fixing bacteria (Rhizobia spp.) can break down the strong triple chemical bonds of N2, the inert gas that forms most of the atmosphere (78%), turning it into ammonia (NH3). These bacteria invade the root hairs of legumes forming nodules. The plant gives sugar and a safe home for the bacteria in exchange for the ammonia, a bio-available form of nitrogen that the plant can use. Other nitrogen-fixing bacteria (e.g. Frankia spp.), associate with shrubs like alders (Alnus spp.).

Legumes, such as this White Prairie-clover (Dalea candida), associate with nitrogen-fixing bacteria, increasing the fertility of the soil. © The Manitoba Museum.

A second important mutualism is between plants and mycorrhizal fungi. Fungi are good at obtaining water and minerals partly because they have a much greater surface area than plant roots (about 50 times as much), and partly because they produce special chemicals that helps them obtain insoluble minerals. The fungi wrap around and penetrate plant roots with their hyphae (fine hair-like structures) so that the organisms can exchange nutrients: sugar from plants to fungi, and minerals and water from fungi to plants. Mycorrhizal fungi are about 100 times more effective at obtaining water than plant roots alone, aiding in drought-tolerance. This association allowed plants to colonize land over 600 million years ago, and even today well over 90% of all plant species need mycorrhiza to grow. Plants are so interconnected with each other and the fungi under ground that scientists have started calling this system “the wood wide web”. For our sake, let’s hope that this system, essential to all life, never crashes.

The hyphae of the Biocolored Deceiver (Laccaria bicolor) fungus, wrap around the roots of Red Pine (Pinus resinosa), helping it get enough minerals from the soil. © Hugues Massicotte

Thanks to Hugues Massicotte (University of Northern British Columbia) for the images of mycorrhiza, and Raf Otfinowski and Victory Coffey (University of Winnipeg) for the nematode image.

09/02/20

Closed for Business

Closed Gentian (Gentiana andrewsii) was always a puzzle to me. When I first saw a picture of it in a field guide, I assumed that the photographer had simply taken the picture before the petals fully opened up. It was many years before I finally figured out what this plant’s deal was.

Closed Gentian (Gentiana andrewsii) grows in wet prairies, such as those at the Tall Grass Prairie Preserve near Gardenton, MB.

Back in 2004, while doing field work out at the Tall Grass Prairie Preserve, I had to walk past a few Closed Gentian plants to get to my research plots where I was studying pollinators. Every day I would think to myself, “when are those flowers finally going to open up?” Then one day as I walked past one, the whole plant vibrated. I paused, waiting to see what was going on. Suddenly, one of the fattest bumblebees I’ve ever seen pushed its way out of the flower and flew to another one, pausing briefly to nibble a small hole in the tip before pushing her way in. The proverbial light bulb went off in my head: the closed petals was this gentian’s way of preventing small insects that may be less-effective pollinators, from getting its precious nectar and pollen. Brilliant! I even came across a great video showing this behavior (https://www.youtube.com/watch?v=vDCrQzojP84).

Bumblebee visiting a Closed Gentian. (c) Gerrie Barylski. Used with permission.

Although there are many plants in the tropics that rely on very specific pollinators, this phenomenon is less common in Canada: most plants here rely on a wide range of pollinators-bees, flies, butterflies, moths and beetles-some over a hundred species. However, the only other type of pollinator besides bumblebees that can visit Closed Gentian are hummingbirds, which stick their long bills into the tip of the flower to access the nectar.

This model of Closed Gentian will be in the new Prairies Gallery.

I was so delighted with this plant that, many years ago, I asked our Diorama Artist to create a model of it, complete with a bumblebee butt sticking out, for a temporary exhibit on pollination I was doing. My plan was to eventually put this model in a permanent exhibit. At long last this lovely model will finally be on display in an exhibit on pollination, along with a hovering hummingbird, when the new Prairies Gallery opens up this fall.

07/08/20

Identifying a Ghost Plant

A week ago I posted a blog about a rare plant that I had been searching for in the West Hawk Lake area: climbing fumitory. Since then I’ve had several people ask me how to tell this plant (shown in in the picture above) apart from other similar species. In Manitoba there are only five species in the fumitory family and they are fairly easy to tell apart: two are rare and found in the southeast (climbing fumitory and Dutchman’s breeches), one is a weed from Europe (common fumitory) and the other two are fairly common in open woods and clearings in the boreal forest (corydalis).

Bleeding heart (Dicentra spectabilis). From Wikimedia Commons victorgrigas / CC0 .

All the plants in the fumitory family look somewhat similar to the common garden plant known as bleeding heart (Dicentra spectabilis), shown above. I think every child in the prairies has observed the heart-shaped pink and white flowers of this spring-blooming species before. I’ve got several in my yard that were probably planted when the house was built in the 1950’s. The leaves of species in this family are divided and almost fern-like in appearance. The flowers have four petals but they are irregularly shaped; that is, they are not all identical to each other, similar to snapdragons or orchids. The two inner petals are a different shape from the two outer petals. The outer petals may be mirror images of each other (e.g. Dutchman’s breeches, climbing fumitory) or dissimilar (corydalis). Although these plants are often lumped in with the poppy family (Papaveraceae), some sources (i.e. Flora of North America) consider them unique enough to be in their own family, the Fumariaceae.

Pink corydalis (Corydalis sempervirens) has pink and yellow flowers and long seed capsules.

Ecologically the plants in this family are poisonous (so no nibbling). Insects, however, enjoy the nectar found in the petal spurs. To get the nectar, long-tongued pollinators have to pry the outer petals apart, in the process rubbing up against the male (stamens) and female (pistil) parts of the flower, resulting in fertilization. However, some shorter-tongued insects have figured out that they can get the nectar just by nibbling a hole in the petal spur. See if you can find any of these cheat holes in the plants that you observe in nature.

Golden corydalis (Corydalis aurea) is a common herb in open areas in the Boreal Forest.

The seeds of the two corydalis species and Dutchman’s breeches have elaiosomes attached to them. These are fatty packets that ants like to eat. Ants pick up the corydalis seeds that pop out of the capsules when ripe, and carry them off to their nests where they chew the elaisomes off, leaving the seed onthe disturbed ground near the ant nest.

Here’s an identification key to the plants of the fumitory family (Fumariaceae) found in Manitoba. To use this key, select the statement that best describes your plant until you arrive at a species name rather than a number.

1. Plants are vines that climb up trees or rocks using tendril like-leaflets; petals almost completely fused together with a spongy texture………………………………………………………………. Climbing fumitory (Adlumia fungosa)
1. Plants are herbs not vines; petals fused only near the base, not spongy……………………………….…………..2

2. Both outer petals with a spur………………………………………….Dutchman’s breeches (Dicentra cucullaria)
2. Only one outer petal with a spur……………………………………….………………………………………………………….3

3. Flowers pink; fruit rounded, not splitting open; seeds lacking appendages…………………….………………..
……………………………………………………………………………………….…..Common fumitory (Fumaria officinalis)
3. Flowers yellow or pink with a yellow tip; fruit a long capsule that splits open; seeds with small appendages (elaiosome)…………………………………………………………………………………………………………………….…………..…4

4. Petals pink tipped with yellow; seeds to 1 mm diameter………..Pink corydalis (Corydalis sempervirens)
4. Petals yellow; seeds to 2 mm diameter……………………………………..Golden corydalis (Corydalis aurea)

Dr. Diana Robson

Curator of Botany

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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.