Botanizing With Seek at Indiana Dunes National Park

Things were going our way as we pulled into Indiana Dunes National Park. Swinging around the south side of the Great Lake on our way to Michigan from Chicago, we decided Indiana Dunes would be a good spot to see the shoreline. The cheerful attendant at the gate offered different options for admission. One was a $20 yearlong pass to all national parks for a senior like me. Now, that's a major perk for what still seems pretty modest longevity. 

A visit to the Chicago area offers a chance to see some wonderful restorations of the region's native habitats--prairies, oak savannas, wetlands, dunes--achieved over decades, in part through a consortium known as Chicago Wilderness. Bur oak savannas had disappeared altogether under a sea of nonnative buckthorn, and had to be recreated through botanical research, invasive plant removal, and the reintroduction of fire. 

It was surprising to learn that the Indiana Dunes, a product of receding glaciers and fluctuating lake levels that exposed sandy beaches to the wind, is the fifth most biodiverse national park, and is called the "Birthplace of Ecology." In 1986 Professor Henry Cowles of the newly formed University of Chicago started bringing his students to the dunes to study how a plant community develops over time. The dynamic dune landscape provided a gradient of stability ideal for studying plant succession, from the raw windblown sand of the lakeshore to the complex diversity of species growing on the older, more stable dunes further inland.   

Many of the dunes were mined and carted away long ago for sand. That any survive is a long story, told on wikipedia, featuring Chicago botanists and conservationists like Henry Cowles and Jens Jenson. Some credit for preservation is also due to a woman who in 1915 abandoned city life in favor of a shack on the dunes. Drawn to the spiritual power of the landscape, Alice Mabel Gray became known as "Diana of the Dunes", and advocated for their preservation. She's featured on the interpretive signage in the park.

"Her unusual, free-spirited lifestyle fascinated local townspeople and newspaper readers here and across the country, bringing national attention to the Indiana Dunes at a critical time of early conservation efforts."

Alice Gray's story triggers memories of Thoreau, and a character who lived on the beach in one of Steinbeck's novels--Cannery Row or Sweet Thursday. Thoreau spent two years at Walden Pond; Gray lived on the dunes for nine. 

For me, it was a chance to botanize. The pleasure of learning plants--their names, their shapes--is that you'll encounter the familiar no matter where you go. If you've gained some familiarity with the plant world, you'll find a lot of New Jersey in Indiana, and vice versa.

Look! There are the three shapes a sassafras leaf can make,

and the scalloped leaves of witch hazel. 

And for those plants I didn't readily recognize, I had an ambassador in my pocket, ready to provide an introduction. The phone app I use is called SEEK--a popularized version of iNaturalist. The fun thing about it is that you can point your phone's camera at a plant and the plant's name will appear on the screen. No need to take a photo. It's as if an ID label were hung conveniently on nearly every plant you pass by. 

This shrub, with its three leaflets and distinctive seedpod, reminded me of bladdernut (Staphylea trifolia)--a large native shrub that grows in only a few locations in Princeton's nature preserves. SEEK--my "pocket botanist"--called this dune plant Common Hoptree, Ptelea trifoliata. Turns out that bladdernut and common hoptree are related, being in the same Order: Sapindales.

The pine trees perched on the dunes looked familiar, with their short, paired needles. SEEK, with infinite patience, reminded me: Jack pine. I read about them fifty years ago when first discovering the elegance of fire ecology. Jack pines have serotinous cones that only open when heated by a fire sweeping through. The seeds then fall on the mineral soil ever so conveniently left exposed and fertilized by the flames--yet another clever adaptation of plants to periodic fire. In the midwest, and even in New Jersey, the reintroduction of fire into the landscape, in the form of controlled burns, has been an important element in the restoration of habitats like prairies and oak savannas.

SEEK reassured me that this was in fact winged sumac, just like the winged sumacs that have been spontaneously popping up as we restore the habitat in the Barden at Herrontown Woods. Maybe not "just like." The characteristics of a species can vary across its range, like accents in speech. 

There's a whole long list of invasive species that supposedly grow on the Indiana Dunes, but I didn't see any. What a great feeling to visit a habitat where native plants are thriving. The one weed I saw was the native horseweed. It can cover whole farm fields, but here one was growing all by its lonesome, as if on display, in a crack in the concrete. 

Another bit of luck: a threat of rain had kept the crowds away, making us one of the few witnesses to a beautiful beach and highly swimmable Lake Michigan water. Having arrived with no expectations, the beauty and a cool swim sustained us through the rest of a day of travel.

A few observations collected on the SEEK app:

Common Hoptree, Ptelea trifoliata

Tall boneset, Eupatorium altissimum

Shining (winged) sumac. Rhus copallinum

Flowering spurge, Euphorbia corollata

False boneset, Brikellia eupatoriodes