Around the year in Maple Grove Forest Preserve

This post is the transcript of a 6 minute, 40 second presentation I delivered on September 7, 2019 at the Downers Grove Art Department’s PechaKucha, an event in support of the Downers Grove art community. The evening featured 7 speakers on a wide range of topics, from a Downers Grove resident who became an internationally-known opera star to competitive diving and biohacking.

For more on The Art Department, a subcommittee of the Downers Grove Marchers, and the great work they are doing to foster the arts and dialogue in Downers Grove, visit their public Facebook Page.

Around the year in Maple Grove Forest Preserve

[1] If you walk west from Emmet’s Pub by the straightest route you can, cut through the parking lot across from Immanuel Lutheran Church to Brook Lane and Turvey Road, you’ll reach the edge of Maple Forest Preserve, an 80-acre sugar maple forest purchased from Marshall Field III by the Village of Downers Grove 99 years ago. I find something new there every week.

[2] 2019 started too warm. By Christmas, spring beauty corms had already started putting out shoots and straplike leaves. This species is a spring ephemeral, built to grow fast, sop up sun and vitamins, flower, set seed and die back before the tree canopy leafs out. This year’s shoots emerged about three and a half months early.

[3] Perhaps more surprising was the false rue anemone, looking on January fifth as I’d expect to find it in mid March. Slower to flower, it should be less nimble than the ephemerals. That same day I found wood violets, wild ginger shoots, earthworms churning the soil. Human-caused climate change is an experiment whose outcomes will continue to surprise us.

[4] A week later, there was snow, thankfully, because by the end of the month the bitter cold had arrived. Snowpack helps plants, insects and spiders, earthworms and small mammals survive the coldest weeks of winter. Its crystalline arms interlink to form an insulating blanket, the base of which evaporates away as the earth warms it, leaving a gap for life at the forest floor.

[5] Mice and meadow voles party under the snow all winter long, gnawing at deer antlers and leg bones, living on cached seeds and tree bark. Owls and coyotes can hear them through the snow, but they are safer underneath than above. Still, their trips up top become inscribed in the snow as they gallop the length of a fallen log or snowplow between burrows.

[6] A downed tree in January reveals dark zone lines that fungi lay down at their frontiers. The fungi are devouring the dark lignin that makes plant cell walls rigid, leaving the rotted wood white. We see the fungus bodies, but it is the white rot that shapes the forest, transforming wood into soil while we’re inside reading and listening to the radio.

[7] Honey mushroom rhizomorphs similarly become visible as bark disintegrates from a fallen oak tree. During the growing season, they invade roots of uninfected trees and work their way up beneath the bark, where the fungus infects the wood and causes decay. They aren’t more prevalent in the winter, but they are obvious even when the edible mushrooms aren’t visible.

[8] By mid March we start seeing spring wildflowers. They all have their strategies. False mermaid germinates in late fall, then emerges as a seedling in early March. It absorbs as much sunlight as it can through April, forms green carpets in the forest understory, sets seed, then dies back as the leaves come out on the trees, leaving trails of yellow foliage and warty nutlets.

[9] Wild leek takes a different tack. It’s a spring ephemeral, spreading broad, thin leaves in March through May that wither as the trees leaf out. You’ll think perhaps that you’ve missed the flowers, but watch for the scapes in early July: after 7 weeks of nothing, they’ll emerge, come into full flower by the end of July, and form dark seeds near the end of August.

[10] Other wildflowers take a longer view. Wild ginger doesn’t emerge until 3 or 4 weeks after the false mermaid. The leaves unfurl as they loose themselves from the soil, then produce a raw-meat colored flower at the soil’s surface. The berries ripen by mid June, seeds crested with a nutritious elaiosome that entices ants to drag them into new territory.

[11] As spring wildflowers peak, songbirds migrate, taking advantage of the insects awakening in the warming canopy and tree bark and the opening buds. Most visible among them are the warblers, which in spring are in their glory, singing and in full color. They are vulnerable, too. This black-and-white warbler struck our window at the Arboretum, but recovered to fly away.

[12] June arrives with an onslaught of sedges. There are roughly 140 species in the Chicago region, and they are in every habitat. Carex davisii was my favorite sedge find of the summer, one of only two populations known in the county. Knowing the sedges, wrote Annie Dillard, makes the “least journey into the world… a field trip, a series of happy recognitions.”

[13] The first of July this year I came across a spongy fallen maple bristling with what appeared to be bright red, tiny toadstools with caps less than a millimeter in diameter and threadlike stalks. I posted the photos online and heard within hours from a Tasmanian naturalist that they were in fact slime molds, protoplasm lurking in open sight.

[14] I’d been missing a whole branch of the tree of life on my walks. Two days later I returned to find at least five species: pin-sized “toadstools,” mungbean-sized “puffballs,” grains of rice suspended by threads, pincushions on the sides of logs, an undifferentiated yellow plasmodium. Next year, I’m hoping for slime molds everywhere.

[15] In August, jewelweed spreads its leaves like a bridge between spring and fall, forming hummocks in the floodplain of St Joseph Creek, bearing open-pollinated flowers, closed flowers that can only self-pollinate, explosive fruits, and gall midges wrapped up in blisters along the leaf midvein or wrapped tight in galls that dangle like chickpeas from the shoot tips.

[16] By end of summer, leaf-miners have etched trails across elm-leaved goldenrod, white snakeroot, and white bear sedge, which looks like a monochromatic map of the London Underground. Joe-pye weed leaves are rolled and chewed and mined. Cavities in the elm leaves rattle as though they were enclosed in cigarette paper. Jewelweed leaves are a tangle of slug tracks.

[17] What will come next? It’s fungus season, and as September burns on toward the first frost, puffballs spread out across the forest floor and brown and dry out, spreading spores at a slap or stomp, if they don’t get collected fresh and cooked up. Chicken of the woods and orange mycena emerge from decomposing trees beside white jelly fungi. The year gives way to rot.

[18] In the coming months, the seeds of late summer and fall will ripen and disperse. American pokeweed berries will darken like plums over the coming weeks. Elderberries already have. Acorns are ripening on the bur and white and Hill’s oaks, and they are falling from the red oaks. Joe-pye weed achenes will fly away as October comes on.

[19] Before we know it, chlorophyll will break down in the sugar maple leaves, exposing the xanthophylls, carotenes, anthocyanins that form the yellows, oranges and reds that we flock to the woods to see. If the tree has time, at the base of each petiole will form an abscission layer that cleaves the leaf from the tree and seals the scar in one stroke. Fall will have ended.

[20] Then winter will begin again, and as the squirrels gather acorns they cached in September, there will be new things to see, each and every day. I could spend my whole life exploring this 80-acre forest down the street and still have more to learn. One good forest is enough for a lifetime.


For additional reading on a few of the slides above:

[1-3] The account of this winter’s precocious spring wildflowers is written up in my January 6 blog post, with photos and identifications.

[6] The Wikipedia article on spalting describes different causes of fungal wood discoloration, and explains in brief how zone lines are formed by white rot fungi.

[12] My post Various forms of happiness describes this past year’s sedge season, with photos and identification of severl of Maple Grove’s species.

[13] Cohen, Arthur Le Roy. 1969. Slime molds (slime fungi). In: Encyclopaedia Brittanica, Volume 20. William Benton, Publisher, Chicago. Also, my post What Fiction Could Only Imagine, on the slime molds of Maple Grove

[19] An outstanding article by Ted Levin, “The Causes of Fall Color,” from Northern Woodlands, 2002.

Another door has opened

Elm-leaf goldenrod is blooming, jumpseed fruits are starting to drop, red oak acorns are falling all over the woods.

Tuesday night, our dog Brooklyn and I arrived at Maple Grove Forest Preserve at 7:30. Jumpseed fruits at the edge of the forest had ripened to the point that about a quarter of them sprung from the plant when I ran the inflorescence through my fist. Beggar’s ticks were almost ripe, sticking to the roughened tips of my fingers, with a single white flower at the tip of each inflorescence branch, a swollen ring of nectaries surrounding the mouth of the corolla. Jewelweed formed hummocks in the floodplain of St. Joseph Creek. A white-breasted nuthatch called. Crickets blasted from the tree tops. Brooklyn studied the water striders in the water flowing under the bridge, then barked at them, hair raised along her spine. She was on full alert.

Within the woods, where it was cooler and moister, the jumpseed fruits had not yet started jumping. Wild leek scapes emerged from the leaf litter like skeletons, the ripening seeds reminiscent of bony knuckles. Chicken of the woods was pumpkin-orange in the dark understory. Joe-pye weed flowers perched feathery and light atop towers of foliage. As the sun set, I started noticing mosquitoes. It quickly became too dark to get good photos without a flash or an exceptionally steady hand. An eastern wood-pewee called.

By 8:00, the crickets were singing continuously. Brooklyn and I passed a great blue lobelia at the edge of a marshy opening in the woods and headed up to the top of the hill. Burdock was in bloom. I had picked up a red oak acorn along the way thinking I’d float it out when I got home, but I realized on the way up the hill that some insect had gnawed the top out of it. I had hoped to find at least a dozen full, heavy fallen red oak acorns and float them out, see how many are viable now, but in the darkness I could scarcely find any. At the top of the hill, where the forest opens up to the lawn and parking lot, a cicada fired up in the canopy, the last of the evening, and warbled its spinning call dopplerlike until it rattled out of steam and was quiet. The pewee called again.

Turning back into the forest on the way down the hill, we were back in darkness. The mosquitoes became aggressive, swarming all around my face. Brooklyn started eating grass and panting. She gets nervous in Maple Grove. She was pulling on the leash and I was pulling back to slow her. We passed behind the Avery Coonley School, which was lit up for open house, perhaps. It looked like a school dance was going on, and there was music and noise from every window. Halfway down the hill, a great horned owl called. We kept walking, then it called from directly above us. Brooklyn stopped, looked up, then dragged me downhill. We raced through the marsh where meadow grasshoppers called and rice cutgrass pulled at our ankles. We passed the giant fallen ash where the sunny gap in the canopy pools with jewelweed. We passed the ephemeral pool filled with hop sedge, up to the trail, across the bridge over St. Joseph Creek, and back toward the car.

We were the only ones left at the parking log. The field pooled with mist leaking from the grassy slopes. The air was filled with cricket songs.


After work on Friday, about 4:30, we came back to do exactly the same walk. The mosquitoes were dormant. The crickets sounded anemic in comparison to their exuberance of nighttime. Nutlets on the musclewood were hard enough to break your teeth. White avens infructescences shattered easily between the fingertips. Elm-leaf goldenrods had come into flower and their leaves were excavated by leaf miners. Black snakeroot fruits were still hanging on… do they never drop? Again Brooklyn stopped on the bridge, poked her snout between the rails and barked at the water flowing underneath, hackles raised. Were there little fish in there? Water-striders on the surface? I looked with her but couldn’t see a thing.

In the light of late afternoon, the wild leek fruits looked nothing like skeletons. I hardly noticed them. The soil beneath the wild ginger leaves was crumbly and moist, worked over. Do earthworms favor the ginger? I came across greater celandine leaves but found that the latex has lost its color. Sugar maple seeds were strewn over the leaf litter, and I could find many more ripe red oak acorns this time. I gathered as many as I could carry in my pocket, focusing on the ones that appeared to be in good shape. From the trail, a cluster of orange mycena mushrooms stood out against the spongy rotten log on which they were growing. Elsewhere in the woods, there were deer mushrooms pushing up from the soil, and turkey tail fungus fringed the full length of fallen logs, bark still intact: perhaps in a decade or so these logs will be too rotten for turkey tail fungus, and the orange mycena and slime molds will move in. In rotting leaf litter were Marasmius capillaris, the most delicate of mushrooms, with wiry black stems and caps scalloped and glistening. At the edge of the trail, a six-inch section of the bone of a deer leg, I believe, was gnawed down at the ends by mice or squirrels in search of calcium. The marrow inside had been devoured.

Near the top of the hill there were wingstem and giant ragweed in bloom, white snakeroot still flowering–it’s been going strong for weeks now and is near its end–Joe-pye weed achenes darkening inside the heads, which are still being visited by bees; pale jewelweed bearing closed, cleistogamous flowers1 and open-pollinated flowers alike, with slug tracks across the upper surfaces of the leaves and, on some plants, galls hanging from the petioles2; late-season flowers on common agrimony and American pokeweed, which was largely in fruit; ripe achenes on hooked buttercup; flowers on clearweed and whitegrass, a less aggressive cousin of rice cutgrass. Black elderberries looked delicious, dark and glossy.

From the lower branches of a white oak at the top of the hill, near the parking lot and the picnic tables, where we had listened to the last cicada of Tuesday evening, an eastern phoebe was flycatching. It sallied out a few feet, grabbed an insect, flew back to the branch to wait for the next opportunity. After watching it for a few minutes, Brooklyn and I started back down the hill, and a glossy black cake of fungus on a log lying next to the trail caught my eye. It was a pearled wonder, like a fly’s eyeball. Had I never seen this thing? Assuming I have the family right (Hypoxylaceae is my current best guess), there are representatives sparsely everywhere in eastern North America. Another thing to watch for in late summers of the years to come.


Brooklyn was happy to get back to the car. When we got home, I started a pizza, skyped a colleague in Morelia (about oaks, of all things), and floated out the red oak acorns. Of 17, four sank immediately. By the next morning, only half were still floating. It struck me as not that bad, about 50% good acorns. The tree might see it differently however. All those acorns made, at such expense, that had no chance of growing. All the acorns I skipped because they were runty. All the acorns that were devoured on the tree, filled with insect eggs before they could grow, dropped hollow behind a trunk and became a home for mites.

When does the forest year begin? How many mornings are left? The September calls of great horned owls, the emergence of wild leek leaves in spring, yellowing of toothwort at the end of May, doll’s-eye berries ripening, the first frost. A door has closed. Another door has opened.3 Why not start the forest year this weekend, with the red oak acorns raining down to their various fates? I only tested 17. That leaves a lot back out in the woods that we can hope will be hardening off as seedlings this time next year, just in time for school to start again.


Plants referenced:

  • Acer saccharum – sugar maple
  • Allium tricoccum – wild leek
  • Ageratina altissima – white snakeroot
  • Agrimonia gryposepala – common agrimony
  • Ambrosia trifida – giant ragweed
  • Arctium – burdocks
  • Asarum canadense – Canadian wild ginger
  • Carpinus caroliniana – American hornbeam
  • Chelidonium majus – Greater celandine
  • Elymus hystrix – bottlebrush grass
  • Euphorbia maculata – spotted spurge
  • Eutrochium purpureum – Sweet Joe-Pye-weed
  • Geum canadense – white avens
  • Hackelia virginiana – stickseed, beggar’s ticks
  • Impatiens pallida – pale jewelweed
  • Leersia oryzoides – rice cutgrass
  • Leersia virginica – white grass
  • Lobelia siphilitica – great blue lobelia
  • Persicaria virginiana – American jumpseed
  • Phytolacca americana – American pokeweed
  • Pilea pumila – Canada clearweed
  • Quercus rubra – northern red oak
  • Ranunculus recurvatus – Hooked buttercup
  • Sambucus canadensis – American black elderberry
  • Sanicula canadensis – Black Snakeroot
  • Solidago ulmifolia – elm-leaved goldenrod
  • Verbesina alternifolia – wingstem

1 You can read more about cleistogamous flowers in jewelweed in my post A running description of the present, from June 23 of this year.
2 The gall is I believe from the gall midge Schizomyia impatientis.
3 “You ask yourself, How many mornings are left? / A door has closed. Another door has opened.” Paul Auster, 2012, Winter Journal, p. 230. Henry Holt and Company, LLC, New York.

Next to clouds even a stone

Next to clouds
even a stone seems like a brother,
someone you can trust
— Wislawa Szymborska

A month ago, the Tuesday morning that comes precisely in the middle of July, I arrived at the East Woods just after sunrise. The mosquitos didn’t strike me as too bad while I was tying up my bike, but walking through, I stopped to make a note, and my arms were suddenly covered with them. Rain was on its way, and with the falling barometer they were ferocious. My notes were illegible all morning long. “Circaea frs” I wrote, which is clear enough. But what can I make of the second half of that line, which appears to read, “phuptopastB still weifs?” When the mosquitoes are that bad, you don’t bother writing more than you need to. For the Circaea (enchanter’s nightshade) fruits, I do know what I was saying: they are filling out, getting downright plump and bristly, though some are still tipped with white flowers (“still weifs”). Wood nettle inflorescences were white and feathery, not open yet. False nettle inflorescences were erect, anthers just emerging. Sweet cicely fruits were as black as grains of wild rice, and some plants were starting to die back, and galls of Neolasioptera impatientifolia dilated the midveins of the pale jewelweed leaves. Woodland tick-trefoil was caught between blooming and fruiting. As I write this, nearly a month has passed, and it is still flowering and fruiting.

Basswood fruits were swelling, and the woodchipped trails were littered with fallen flowers. The mosquitoes were evidently still awful as I wrote that along “one stretch, woodchips were 50% Tilia flowers,” as there is a smear of blood across this note. American bellflower was in bloom, Joe-pye weed flowers were still not open. Black snakeroot fruits were hardening by now, releasing from the inflorescence readily, sticking to the band-aid on my thumb. Yellow violet capsules were almost all opened. Silky wild rye inflorescences were bristling with spikelets. Jumpseed fruits were still soft. Black elderberries were forming. The flowers were falling to the ground.

Two mornings later in Maple Grove, the wild leeks were straightened out from their arching of two weeks earlier, inflorescences expanding, though the flowers were still not open on most. Water plantain leaves had emerged in the ephemeral pond, and there were white jelly fungi on the fallen rotting logs. Honewort fruits were rubbery and there were red oak shoot tips scattered on the forest floor, bearing aborted acorns. Chokecherry fruits were ripe. At work, the East Woods were starting to wake up to the glory of woodland sunflowers. Crownlike fruits were growing on agrimony, white avens burs were as big as marbles, lopseed fruits were all reflexed but not ready to spring off yet. Joe-pye weed leaves were all mined and chewed and rolled, so you could hardly imagine they were doing the plants any good. The bottlebrush grass spikelets were thick and brittle and scattered at a touch. False Solomon’s seal infructescences were heavy with ripening fruit. Walnuts that two weeks earlier would have been about the size of the overgrown shooter marble my great grandpa gave me when I was young had grown as large as apricots. Nettle-leaved vervain was lit up with tiny white flowers. That evening, I returned to Maple Grove to find the canopy gauzy with cicadas. White snakeroot had come into bloom — possibly that very day? The first leaf-miner traces had appeared in the evergreen leaves of white bear sedge. Wild leek, which I swear had barely been in flower that morning, stood out like a colony of mushrooms. A solitary blue cohosh fruit was bright blue; the rest were hazy. Stickseed had started to flower.

That weekend and the entire next week were filled with work and with evening walks with the boys and the dog. I cannot tell you what I saw that week, if anything. The weekend, through Sunday when I left for the cab, I worked on my talk for the Botany conference. The next day, the last Monday morning in July, just after midnight, I arrived in Tucson, slept a few hours, and then took a cab to Starr Pass for the conference with a graduate student from my lab. I had been seeing tweets of the flora for several days, shots of saguaro cacti out of hotel windows, but I wasn’t prepared for it. The landscape was otherworldly, rock and hills covered with 15′ tall saguaros, prickly pear cacti in fruit. Only 6,000 years ago there were camels here, and they and the ground sloths ate these spiny things. There were Zygophyllaceae, Malpighiaceae, Simmondsiaceae, families you run across relatively rarely in Downers Grove. There was dragon’s blood, a Euphorb named after the color of the latex. I’ve inspected its DNA sequence, but I’d never seen it. After a rain one afternoon, the hills were redolent with wet creosote. There were wolfberry and paloverde, barrel cactus and choya, ocotillo, Haplophyton, mesquite, Parkinsonia, fairy duster, rock hibiscus. The second morning of the conference, a friend accused me, “You didn’t tell me Celtis pallida was growing along that trail!” I had to confess that I didn’t even know the plants, and went back to see it. It’s a shrub of a thing, delicate, not something I would have recognized as a hackberry. That is the way with oaks down here as well: you have to relearn the woody plants you thought you knew as you move into the southwest and Mexico, because they have learned new tricks and don’t look so much like their cousins in the east. Black-throated sparrows called like mechanical, efficient song sparrows. There were black-tailed gnatcatchers. If we had been there at the right time, we might have seen white-winged doves with their faces buried in the saguaro flowers, faces covered with white pollen.

Each morning we hiked, each day we listened to talks. The origin of land plants. The evolution of Viburnums and basswoods. Application of machine learning to plant science. On the last morning walk I learned about the two species of woodpecker that specialize on the tops versus the bottoms of the saguaros. That evening, we talked about how we can train our students to be scientists outside the academy, to make careers of their PhDs in a world where the number of smart, hard-working PhD-trained plant biologists far exceeds the number of academic jobs. That’s a lot of landscape to cover in 15 hours.

On the flight out of Tucson the next morning, the rising sun cast the mountains into sharp relief beneath clouds spread thin like cottonwood seeds on a stream. Images and sounds from the preceding days elbowed each other on their way to my prefrontal cortex. The cactuses mixed with the phylogenies, the song of the black-throated sparrow echoed over a lecture about trait relationships in the Wisconsin flora. By turns, these moments all stood clearer against each other, like the east and west faces of the Tucson mountains as the sun rises and the doves call; then they faded into one another. Viburnums radiated in parallel on their way down to Mexico, sneaking between the saguaros outside the lecture hall. Jojoba fruits drifted across screenshots from a database that holds plant records from Peoria and the Chiracahuas. As we flew over the Great Plains, the clouds tumbled like cotton batting, “cruis[ing] smoothly over your whole life / and mine.”1 Roads and fence lines were etched into the soil at right angles, broken by gallery forests. A bridge cut across a stream. One field abutted another, contrasting colors. The conference and the hikes were juxtaposed, then blended together and, as we touched down, separated cleanly from the woods I hike each day.

So much more has happened in the past month, with our long hot days, and even more that I’ve missed. One morning at the end of July, woodland sunflowers started coming into bloom in the East Woods. Sometime around the beginning of August, I realized the robins weren’t singing in the morning anymore, that they’d been replaced by cardinals. Did they pass the baton one morning while I wasn’t paying attention? In the past two weeks, Solomon’s seal berries, doll’s eye berries, lopseed and agrimony fruits have ripened, and bur oak acorns are swelling in the East Woods. Last night there were white jelly fungus and chicken of the woods on the rotting logs in Maple Grove Forest Preserve, wild leek and black elderberry fruits ripening, wingstem and cutleaf coneflower blooming, a fallen red oak acorn that looked full and healthy but was rotted inside.

As I write this, lightning is striking within an eighth of a mile of our house, rain is falling hard, and the dog has snuck onto our bed to sleep off the dash we made home in the first downpour of the morning. We still have a month of summer to look forward to.


Plants referenced:

  • Ageratina altissima – white snakeroot
  • Agrimonia gryposepala – common agrimony
  • Alisma subcordatum – American water plantain
  • Allium tricoccum – wild leek
  • Campanulastrum americanum – American bellflower
  • Carex albursina – white bear sedge
  • Circaea canadensis – enchanter’s nightshade
  • Cryptotaenia canadensis – honewort
  • Desmodium glutinosum – woodland tick-trefoil
  • Elymus hystrix – bottlebrush grass
  • Elymus villosus – silky wild rye
  • Eutrochium purpureum – Joe-pye weed
  • Geum canadense – white avens
  • Hackelia virginiana – stickseed, beggar’s ticks
  • Impatiens pallida – pale touch-me-not, pale jewelweed
  • Juglans nigra – balck walnut
  • Laportea canadensis – wood nettle
  • Osmorhiza claytonii – sweet cicely
  • Phryma leptostachya – lopseed
  • Polygonatum biflorum – Solomon’s seal
  • Prunus virginiana – chokecherry
  • Quercus macrocarpa – bur oak
  • Quercus rubra – red oak
  • Rudbeckia laciniata – cutleaf coneflower
  • Sambucus canadensis – black elderberry
  • Sanicula odorata – black snakeroot
  • Tilia americana – basswood
  • Verbena urticifolia – nettle-leaved vervain
  • Verbesina alternifolia – wingstem
  • Viola pubescens – yellow violet

1 Excerpts from Wislawa Szymborska, “Clouds.” In: Monologue of a Dog, 2002. Translated from the Polish by Clare Cavanagh and Stanislaw Baranczak, 2006: Harcourt, Inc., Orlando.