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.

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

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.

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.

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.

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?

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.

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.

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.

Once again I am studying pollinators at the Nature Conservancy’s Yellow Quill Prairie Preserve (find more details here) 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.

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.

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.

Image: Wikimedia Commons

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.

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!

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).

Ferguson, B.A., T.A. Dreisbach, C.G. Parks, G.M. Filip, and C.L. Schmitt. 2003. Coarse-scale population structure of pathogenic Armillaria species in a mixed-conifer forest in the Blue Mountains of northeast Oregon. Canadian Journal of Forest Research 33:612-623.

Song Y.Y., S.W. Simard, A. Carroll, W.W. Mohn and R.S. Zeng. 2015. Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks. Scientific Reports, 5 8495. DOI: http://dx.doi.org/10.1038/srep08495

Wohlleben, P. 2016. The hidden life of trees: What they feel, how they communicate discoveries from a secret world. Greystone Books.

Zelmer, C.D. and R.S. Currah. 1995. Evidence for a fungal liaison between Corallorrhiza trifida (Orchidaceae) and Pinus contorta (Pinaceae). Canadian Journal of Botany 73:862-866.

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.

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!

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.

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