Springtime Symbiosis: Trout Lilies and Superhero Ants

troutlily_webJML

Trout Lilies (Erythronium americanum) pop up from the forest floor, tiny harbingers of warm weather to come. This little lily is a spring ephemeral – a flowering plant that takes advantage of that tiny window of time between the last frozen days of winter and the heyday of spring, when the forest canopy selfishly soaks up all the sun’s rays. During those few weeks, the Trout Lily breaks through a ceiling of dead leaves, and slurps up sun and nutrients to store for the rest of the year in its underground bulb. If that’s not enough, that brief time is also used to flower, produce seeds, and make sure the next generation is safely on its way. No wonder this little plant needs a rest for the remainder of the year!

Given the time limitation, the Trout Lily can’t mess around with seed distribution. It has to be done right and done quickly. Call in the ants.

Many spring ephemerals, like the Trout Lily, produce an incentive for ants to take their seeds, move them a distance away, and plant them in a safe, nutrient-rich location. Each seed has a dollop of yumminess on its outer surface, like icing on a seed-shaped cupcake (officially the “icing” is called an elaiosome, a mixture of fats and protein). Ants carry the seeds back to their nests, feed the yumminess to their larvae, and dispose of the seeds in a waste area which just happens to be a wonderfully fertile location for young seedlings to begin their lives.

Not only do ants spread seeds to new locations and give them a fertile spot to grow, they also protect the seeds from predators like mice. Ruhren and Dudash (1) placed seeds in four scenarios on the forest floor: (a) accessible to both ants and mice, (b & c) accessible to either mice or ants, and (d) inaccessible to mice and ants. The researchers found that ants secured the seeds before the mice, saving the little plants’ lives. In locales where these superhero ants have vanished, spring ephemeral populations drop 70% (2).

Want to learn more about the superhero ants (a.k.a. winnow ants)? Visit School of Ants.

  1. Ruhren, S. and M. R. Dudash. 1996. Consequences of the Timing of seed release of Erythronium americanum (Liliaceae), a deciduous forest myrmecochore. American Journal of Botany 83(5):633-640.
  2. Rodriguez-Cabal, M., K.L. Stuble, B. Guenard, R.R. Dunn, N.J. Sanders. 2012. Disruption of ant-seed dispersal mutualisms by the invasive Asian needle and (Pachycondyla chinensis). Biol. Invasions 14:557-565.

Losing our Plants

ATwildflowers_allPlants love CO2. They suck it in to build their bodies and power their lives. The millions of tons of CO2 we spew into the atmosphere each year should make a plant feel like partying. Yet 70% of plants are at risk of extinction (1).

Beautiful Diversity

The image above represents the diversity of wildflowers I saw while hiking on the Appalachian Trail this summer. I’ve researched their historical medical uses (and wartime uses), pigmentation, symbiotic relationships, chemical and physical defenses, anatomy, and impact on insects. I hope you’ve enjoyed learning about these plants as much as I have!

Climate Change and Habitat Alteration

Climate Change brings shifting temperatures and water patterns, introduced pathogens and competitors. Since many plants have such close relationships with insects and fungi, evolutionary change grows in complexity. Most plants can’t keep up.

One of the biggest threats to plants (and everything else) is Habitat Alteration. We change the flow of rivers, turn forests into concrete deserts, build islands and literally move mountains. Geologic shifts like these used to take place over millennia. They now happen in months.

Loss of Plants, Loss of Knowledge

We change habitats to create more space for ourselves – building homes and grocery stores, retrieving fuels for our electronics and cars, and creating a lake-side view where there was none. But as we focus more and more on ourselves, we lose our awareness of everything else.

How many of us can identify the plants in our own backyards? How much medical and agricultural knowledge have we lost because “plants are boring”? When we lived within the landscape (rather than changing the landscape to suit our needs), we were forced to understand the lifeforms around us. We learned which plants to cultivate and which to avoid. We appreciated the benefits and perils of every plant.

Appreciate a Plant Today

Plants supply almost all our food and 1/2 our oxygen (thank you, algae, for the other half). Plants secure our soils and could help us battle Climate Change. Plants make beautiful flowers and support every ecosystem.

Let’s vow to get to know them better. Pick a plant in your yard and ID it. Visit an arboretum or botanical garden. Take a local botany class. And don’t forget to take some time to smell the roses.

  1. http://www.iucn.org/media/news_releases/?81/Extinction-crisis-escalates-Red-List-shows-apes-corals-vultures-dolphins-all-in-danger

Wildflower Stories: The Final Chapter (Horsenettle)

ATwildflowers_horsenettlePlants are masterful chemists when it comes to defending themselves. Turns out, some plants build fortifications too. And these armories may even store deadly microbes for use as biological weapons.

Major defensive structures of plants include thorns, spines and prickles. Did you know they’re different? Thorns, officially, grow from the stem or shoot of the plant. They’re like miniature, pointy branches. Hawthorns and lemon trees, for example, have thorns. Spines grow from leaf tissues. Some leaves develop spinous points; some leaves fully convert into spines (like on cacti). Prickles grow from the plant’s outer surface of cells (the epidermis). Since the epidermis is found all over a plant, prickles can pop out of anywhere. “Thorns” on roses are actually prickles. And the spikes growing all over the leaves of this horsenettle (Solanum carolinense) are… prickles.

horsenettleBut these defensive structures may be more prickly (or thorny?) than we ever imagined. Preliminary research indicates that harmful (even deadly) microorganisms inhabit thorns, spines or prickles and cause further injury to herbivores who dare to challenge the awesome power of plants (1).

  1. Halpern M, Raats D, Lev-Yadun S. The Potential Anti-Herbivory Role of Microorganisms on Plant Thorns. Plant Signaling & Behavior. 2007;2(6):503-504.

Wildflower Stories: Ast(er)ounding!

asters_ATlFavorite flower? Daisy (an Aster, like these).
Not only is it humble and cute, it’s a bargain. For each daisy you buy, you get hundreds of flowers. The disk part of each “flower” is actually a composite of scores of tiny flowers. Look close – you’ll see.

aster_closeAnd the “petals” of a daisy? Each one is actually a whole flower too! The single petal plucked for “loves me” or “loves me not” is actually 5 petals fused over evolutionary time. If you look at the tips, you can still see some divisions.

Here’s another example of an aster – purple coneflower!

Educational Activity: dissect an aster and see all the mini-flowers for yourself!

Wildflower Stories: Part 4 (Minty-fresh poop?)

ATwildflowers_mintBee Balm (Monarda sp.) is a member of the Mint Family – a group of aromatic plants that includes basil, lavender, rosemary, salvia and oregano.

How can you identify a Mint? Of course, the smell is a dead giveaway. That odor is actually a deterrent for herbivores. If a mouse eats a bit of mint, that mint scent will overpower the rodent’s sense of smell. So the mouse won’t be able to pick up a cat’s scent later on.

Some beetles have evolved to resist the essential oils of Bee Balm. When they eat the plant, oils condense in the beetles’ poop. They form the poop into a “shield”, waving it at any potential predators.mint_flower

Wildflower Stories: Part 3 (Red Clover Symbiosis)

ATwildflowers_cloverImagine the extreme thirst of being stranded at sea, encircled by water you cannot drink.  Air is like that. Our bodies need nitrogen desperately to survive – and we’re surrounded by air full of Nitrogen (N2). But it’s all unusable. N2 needs to be converted to NO2 for us to use. Only bacteria can do that.

So what do bacteria and nitrogen have to do with this unassuming little plant? Red Clover (Trifolium pretense) is a member of the Legume Family of plants. Legumes cooperate with soil bacteria, giving them sugars and, in return, receiving “fixed nitrogen” (NO2). This fixed nitrogen inserts itself into all the living structures of the plant and, when eaten, passes the usable nitrogen on to animals.

clover_bee

Until the early 1900s, the only way we could get nitrogen in our bodies was through this route. Then, the Haber-Bosch process was developed. Not only did it save us from mass starvation (yay!), it served as a resource for making bombs (hiss!) and ultimately intensifying World War II.

For an AWESOME read about the Haber-Bosch process, read “The Alchemy of Air” by Thomas Hager. Now if someone would just write an exciting, gut-wrenching saga about legumes and soil bacteria.

Wildflower Stories: Part 2 (Tall Bluebell)

Bluebell_ATwildflowerslSee that Tall Bluebell (Campanulastrum americanum) flower? Is it red or is it blue?

Believe it or not, it’s kind of both!

The color pigment in plants that makes red is called anthocyanin. The pigment normally reflects red light waves. But if you raise the pH and add a couple metal atoms to anthocyanin, it changes the light waves reflected – and poof – blue!

bluebell_flower

Turns out, blue is a pretty rare color in nature. Dr. David Lee wrote a whole book about how colors in nature come to be, including the fairly complex steps to making blue in “Nature’s Palette: The Science of Plant Color”.

If you’d like to check out the color pigments in the flowers around your home, visit Scientific American for an easy, do-it-yourself pigment experiment.