“Not all that bristles is bad: in defense of thistles”


Thistles are plants that are well-known but not well-loved, at least by humans. Admittedly, they don’t often make the best impression on us thin-skinned, hairless apes. We’re just trying to go for a walk and enjoy nature. We already have to deal with poison ivy and ticks, and now we have to watch for plants with tiny little knives on the end of their leaves? C’mon!

Our disdain for these plants probably also has to do with the agricultural roots most of us have. Certain thistle species get into ag fields, and no way are we pulling those things by hand. Even the Bible suggests they are a curse, complements of Adam and Eve’s transgression (Gen. 3:17-18).

The most abundant thistle on the landscape is the poorly-named “Canada” or Field Thistle (Cirsium arvense). It is an invasive species, which means it is both non-native to this continent and causes significant ecological and economic harm. By Indiana law, it is also considered a noxious plant and landowners are legally obligated to take steps to control it (as we do here). It is a stubborn perennial plant that you don’t want in your ag field or your prairie planting. It blooms early, in June. Bull Thistles (Cirsium vulgare) are another common non-native thistle found in our pastures.

But just like those of us who come off as a like “prickly” on first encounter, we should give thistles another chance. There are several native thistles that are “well-behaved,” mixing in easily with other native grasses and wildflowers, and not a weedy problem within agricultural systems.

Pasture Thistle (Cirsium discolor) towards over neighboring plants, loaded with blooms.

Mostly importantly, native thistles are absolute magnets for pollinators, everything from showy butterflies to tiny native bees. Females of the long-horned bee species Melissodes desponsa are oligolectic on thistle pollen, meaning that their larva will not develop on any pollen unless it is a Cirsium thistle species! When thistles disappear, so does this bee species.

On the left is Swamp Thistle (Cirsium muticum), fighting it’s way up through a thick stand of hybrid cattail. I would like to think our prescribed fires have helped remove enough thatch to let a few more of these plants grow and seed.

Tall Thistle (Cirsium altissiumum) is an oak savanna species. Swamp Thistle (Cirsium muticum) has a beautiful deep-purple flower and is found in wetlands, including the fringes of Lake Galbraith. Pitcher’s Thistle (Cirsium pitcheri) is a federally-threatened plant found only on the sand dunes around Lake Michigan.

Bees and Swallowtails are both fans of Pasture Thistle.

But probably my favorite species, which is now in bloom in many of the roadsides in western Marshall county, is Pasture Thistle (Cirsium discolor). It hosts a bright pink (and sometimes white) bloom, nodding high in the breeze. I never fail to find it crawling with pollinators chowing down on the banquet of nectar and pollen. The two year-old plant dies after flowering (it’s biennial), but sprouts easily from seed.

I saw my first white-flowered variant of Pasture Thistle along 9C Road in August 2016.

(You can browse more about all these Cirsium species at the U. of Michigan database).

Neither of the major invasive thistles (Bull & Field Thistle) have this definitive white underside of the leaf, like this Pasture Thistle.

With all these redeeming qualities of beauty and function, surely now you can understand why they bear spikes. They are are an obvious defense against leaf-eating animals. You wouldn’t want to be constantly nibbled on, now would you? See, deep down, thistles are sensitive, reasonable plants on the inside, just making their way in the world. You just need to get to know them.


This post was inspired by Chris Helzer‘s great thistle post from 2015. He also created this great printable/shareable icon to spread the thistle love:

https://theprairieecologist.files.wordpress.com/2015/08/thistlefanclub.png?w=800

news round up

Can’t believe it’s been 4 months already since I’ve posted some links, but here’s your chance to peek over my shoulder at what I’m reading:

Diversifying Conservation (The Prairie Ecologist blog)

It’s Time to Rethink America’s Corn System: Only a tiny fraction of corn grown in the U.S. directly feeds the nation’s people, and much of that is from high-fructose corn syrup (Scientific American)

The zoo beneath our feet: We’re only beginning to understand soil’s hidden world (The Washington Post)


Can the Prairie Generation save rural America? (Christian Science Monitor)

New Evidence Shows Popular Pesticides Could Cause Unintended Harm To Insects (NPR)

Recreational Mowing Syndrome: What is it and how to treat it? (Purdue University)

The Most Controversial Tree in the World: Is the genetically engineered chestnut tree an act of ecological restoration or a threat to wild forests? (Pacific Standard)

A Water Crisis Is Growing In A Place You’d Least Expect It (NPR)

Maine Becomes First State to Ban Styrofoam Containers (USNews)

I work in the environmental movement. I don’t care if you recycle. // Stop obsessing over your environmental “sins.” Fight the oil and gas industry instead. (Vox)

Lake Erie now has legal rights, just like you: Ohio voters passed groundbreaking legislation that allows citizens to sue on behalf of the lake when it’s being polluted (Vox)

NYC Shows How Electric Vehicle Fleets Can Create Dramatic Savings: Recent data from the New York City government reveals the dramatic cost savings for tax-payers by switching to electric vehicle fleets for city operations. (Interesting Engineering)

The legacy of 4,500 years of polyculture agroforestry in the eastern Amazon (scientific paper from the journal Nature)

Earth system impacts of the European arrival and Great Dying in the Americas after 1492 (academic paper)

In Defense of Biodiversity: Why Protecting Species from Extinction Matters (Yale e360)


Humans Are Speeding Extinction and Altering the Natural World at an ‘Unprecedented’ Pace (NYT)

Bill McKibben Calls FBI Tracking Of Environmental Activists “Contemptible” (CleanTechnica)


Marshall County Community Foundation Spotlight – Will Erwin: See the historical wonders of Will Erwin’s Marshall County, Indiana, farm and listen to stories about his service. (a video tribute)

Bioblitz results

Well, it’s a little belated to report, but the 2019 Indiana Academy of Science (IAS) Bioblitz is a wrap! On June 29-30, we had over 30 scientists come from across the state (actually, as far away as North Dakota) to count & collect as many species as they could in 24 hours.

Dr. Jeff Holland, a Purdue forest beetle entomologist, was the bioblitz chair for IAS. I wish I could work with him every day! He is seen here 2 weeks prior to the event, setting up beetle pheromone traps that he would examine the day of the blitz.

This event was a dream of Sr. Mary and myself since the day I started 3 years ago. We were so honored to be selected as hosts for this special event.

When you see this license plate, you know that you’re hangin’ with the right crew.

Lindenwood graciously opened up their doors to host scientists so that they could be well-rested after some brutally hot hours in the field. Our dining services prepared a great evening banquet that the scientists enjoyed out under the tent on the MoonTree prairie. MoonTree staff rolled out the red carpet on snacks, set-up, tear-down, and all manner of logistics. I couldn’t have asked for a better team!

The temperature soared to 90 degrees, but we kept the ice water flowing and made sure folks took breaks.

We gathered at noon on Saturday and made introductions, looked over property maps, and split into teams according to taxa.

Over at the kids table, my little ones were busy painting with plants and making music with natural instruments, thanks to Elsa, one of our Maria Center residents.

From mid-afternoon through the evening, we had tours and talks scheduled for the public. We wanted to provide opportunities for people to engage with scientists in a relaxed environment.

Despite a lot of planning & great efforts made by our marketing staff, we just didn’t have much of a crowd. It was a little discouraging, but I was reminded that our primary goal was to facilitate the work of the scientists and make sure their quality work can go down in the literature for future students of our natural communities. That is something our team did very well, so I was pleased.

Jeremy Sheets, Senior Wildlife Biologist with Orbis Environmental Consulting, shows off the net he uses to trap and study bats.

After dinner, I put the drone up to take a few shots from above.

I even happened to come across the cows going back out to pasture after taking a drink. It made for an interesting aerial shot. I’ve noticed some very interesting patterns in vegetation at the border of grazed and ungrazed areas that are separated by a fence. Another thing to study someday!

We got ready for the evening by – what else? – making some s’mores. MMMm!

As the light died down, the efforts continued. The entomology team set up a couple lights, including a giant 1,000 watt light on a 10 ft pole at the highest point on MoonTree. What happened next was breath-taking (and, you had to be careful not to open your mouth when it happened!)

As much as we might dislike having creepy crawlies inside our home, they are indispensable members of the web of life (outdoors), and human life would simply not be possible without them.

There is increasing evidence that insect populations are facing severe challenges worldwide. It’s ever more urgent that we advance education on insects and press for their preservation.

Dr. Holland reported that this bioblitz was probably the best night he had ever had with the bug light. That made me incredibly happy and certainly made all the effort in setting up this event worthwhile!

The plant team surveys the western shore of Lake Galbraith on Sunday morning.

Sunday morning saw the field crews out and about again, while some others spent the morning looking at specimens under field microscopes in the tent.

Spiders, spiders everywhere! We estimate around 80-100 species sampled from just a small area.

Dr. Holland mounted up several beautiful specimens for us to see under the microscope, like this Ghost Tiger Beetle.

We used the iNaturalist smartphone app to encourage people to log their sightings on our shared project. We could then look at each other’s observations at a single online location. 15 observers logged a total of 120 species, as shown in this screenshot.

We had a great naturalist by the name of Carl Strang, who put in a great effort to survey the singing insects. His meticulous records and photos are a valuable contribution to the scientific record. He recorded a new species for Marshall County in the process, the eastern striped cricket. He also picked up counting the Odonata (dragonflies and damselflies) and Lepidoptera (butterflies and moths), as we didn’t have anyone counting those. Be sure to see his reflection (and photos) on his blog here.

Grape plume moth (Geina periscelidactylus) by Carl Strang
The Hebrew (Polygrammate hebraeicum) by Carl Strang

Tim Rice counted and photographed birds for us. You can see his photos on his Flickr page here.

Common Yellowthroat (Geothlypis trichas) by Tim Rice

We gathered one final time, at noon on Sunday, to talk about preliminary species counts and interesting observations. Unsurprisingly, we found that with the cold, rainy spring, some species seemed to be appearing later in the season than average (we heard a Fowler’s toad calling, which was very rare for late June).

We finished the weekend exhausted, but thankful that we could see so much of Creation on display, in the nooks and crannies and hidden places that we are often too busy to see.

I’ll have to leave you in suspense for the final species count. We won’t really have a good idea until the data can be reviewed during the rest of the summer. Eventually, we’ll put it all together and publish a report in the Proceedings of the Indiana Academy of Science

Until then, keep your eyes and ears open! Expect the unexpected.

The Unexpected Cycnia (Cycnia inopinatus) feeds on Butterflyweed (Asclepias tuberosa) at MoonTree Studios.



talking prairie plants on WNIT’s Outdoor Elements

I had the pleasure to take a trip to Potato Creek recently and share about native prairie plants with WNIT’s Outdoor Elements team. Our segment aired recently and is available online here. WNIT has put together some really great programing, all of which is published online.

Vince Greschem, one of the co-hosts, is a MoonTree Studios elder. He got started in his career at Potato Creek and worked closely with Sr. Mary in restoring the prairies on the property. It was great to look out over her handiwork and appreciate the folks who have maintained those systems in a healthy condition over time

While you’re here, I think I’ll post a few photos of the species we discuss in the program.

Bee balm (Monarda fistulosa) attracted this Peck’s Skipper (Polites peckius), who wasn’t sharp enough to spot the Ambush Bug ( Phymata sp.) who was lurking in the petals. Can you see it? Watch out!
My camera doesn’t do it justice, but this is a Dogbane Leaf Beetle (Chrysochus auratus) that I found at home on my Indian Hemp (Apocynum cannabinum). It’s color seems to change according to the angle at which you view it. Dogbane is in the same plant family, Apocynaceae, as the milkweeds (Asclepias spp.).
Milkweed Tussock Moth (Euchaetes egle) caterpillars on Common Milkweed (Asclepias syriaca) at my home. I never tire of seeing these fuzzy things! The monarch prefers to spread her risk by only laying an egg or two per plant. This moth does the opposite, mobbing a single plant with dozens of individuals, which can devour whole plants.
We didn’t discuss grasses in the show, but I thought the dew-drenched spiderwebs on this Big Bluestem (Andropogon gerardii) were pretty neat.


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