Losing our Plants

Plants 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)

Plants 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.

But 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: Milkweed, Monarchs and Monsanto

Monarch butterfly populations have declined an estimated 90% over the past 20 years. [1] What’s going on?! The answer involves genetic engineering, protozoans and herbicide.

Milkweed (Asclepias syriaca), a member of the Dogbane family of plants, is closely associated with Monarch butterflies. Monarch caterpillars feed on milkweed and assimilate the plant’s chemical defenses, providing the Monarchs protection over the rest of their lives.

Milkweed grows in disturbed soils, like those used in agriculture. The plant is often found between rows of corn or soybeans. However, genetic modification of corn and soybean allows herbicides (such as Monsanto’s RoundUp) to be more efficient at killing other plants, like milkweed. Fewer milkweeds, fewer Monarchs.

So good-hearted people came to the rescue, planting Milkweed in their yards in an effort to help the butterflies. Unfortunately, many people planted the wrong species of Milkweed. Here in the U.S., native Milkweed dies back each year. This dieback limits the population of a Monarch parasite called OE (Ophryocystis electroscirrha). [2] However, the species of Milkweed people planted is evergreen, so the parasites keep proliferating and Monarchs get so sick they don’t survive their migration to Mexico and back.

If you’d like to find the right Milkweed for your neck of the woods, here’s a handy tool from Xerces.

1. http://news.nationalgeographic.com/news/2014/10/141010-monarch-butterfly-migration-threatened-plan/
2. http://monarchparasites.uga.edu/whatisOE/

Wildflower Stories: Ast(er)ounding!

Favorite 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.

And 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 – the Hercules of Plants

Cow Parsnip (Heracleum maximum) has a fascinating relationship with war, GMOs and sunscreen.

The plant’s scientific name probably points to its size – it’s taller than me (but that’s not saying much). It takes two years to grow that big. If you’re going to put that much time into growing, you’ll want to make sure nobody eats you; which leads us to the other possible reason for Cow Parsnip’s scientific name. Some claim Hercules used this plant medicinally.

Many plants contain chemicals to protect them from predators. This plant makes “furocoumarin”. In humans, furocoumarin combines with sunlight to cause a rash. This is where war comes in. During World War II, military organizations recruited plant and insect experts to investigate the defensive (or offensive) properties of these chemicals. Mustard Gas is similar in its blistering effect to furocoumarin.

Most plant predators, though, are not humans; they’re insects. As you can imagine, Cow Parsnip is very effective at deterring insect herbivores. So, the genes that will ultimately produce furocoumarin are prized. If you could insert those genes into another plant (how GMOs are made), the same protection will occur.

Beware the inevitable evolutionary “arms race” that results though. A few insects can eat Cow Parsnip, either due to mutations that let them break down the furocoumarins or behavioral shifts (like eating that plant only at night or when rolled in one of the plant’s leaves. Remember, the chemical has to be combined with sunlight to produce an effect.

And we get to sunscreens. A related chemical was used as a “tanning accelerator” up until 1996. Unfortunately, it caused rashes (“sun poisoning”), skin loss and even cancer. Turns out, furocoumarins can mutate DNA.

Cow Parsnip belongs to the Carrot family of plants. They tend to have hollow stems and flowers in “umbels” (like umbrellas). Some relatives are frequently on our dinner table (carrots, celery, parsley, dill, etc.); some, like hemlock (not hemlock), are deadly.

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

Bee 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.

Wildflower Stories: Part 3 (Red Clover Symbiosis)

Imagine 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.

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)

See 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!

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.

Wildflower Stories: Part 1

The wildflowers along the Appalachian Trail impressed the heck out of me during a recent hike. My inner biologist began counting the number of plant families represented. The artist inside distracted my count with constant “ooo, pretty!” comments. This drawing highlights just a few of the flowers from the trip – and launches the first of a host of posts.

 AGRIMONY (Agrimonia sp.)

Once upon a time, Agrimony was a go-to herb for the local physician. It was reported* to cure or alleviate eye and liver problems, intestinal troubles, back pain, gunshot wounds, snakebites, sore feet, pimples and coughs. The most horrifying treatment combined Agrimony with “a mixture of pounded frogs and human blood, as a remedy for all internal haemorrhages.”¹

We’ve come a long way (thank you, Scientific Method). While Agrimony may contain compounds beneficial to our health, rigorous controlled studies are lacking or do not show the benefits claimed above. Still, Agrimony is sold today as an herbal remedy.

A lack of data doesn’t mean Agrimony won’t help ailments – it doesn’t mean it will either. As a member of the Rose family (the flowers’ many stamens clued me into its familial origins), Agrimony shares traits with apples, lemons, nectarines, almonds, and of course roses. So it’s in good company with a lot of wonderful foods that offer beneficial properties and nutrients.

*This blog does not endorse the use of Agrimony to treat any of these ailments.

1. A Modern Herbal by M. Grieve. 1971. Dover Publications, New York.