Visiting Minnesota--Lovely Forestville State Park

I took a field trip to Forestville/ Mystery Cave State Park during the Botanical Society of America meetings (meeting post). It is a reserve in the driftless region, places the glaciers somehow missed. The glaciers nevertheless rearranged the area, as rivers of meltwater cut deep channels and, slowing, dropped everything from sand to boulders.

Today the area is at the western edge of the great Eastern Deciduous Forest that covered the eastern United States. The forest in Forestville is secondary growth, having been farmland in the 1890s, but progressively abandoned thereafter, officially designated a state park in the 1960s. Minnesota Parks has making a concerted effort to remove weeds and favor native plants. Experts can show you the imperfections, but to a casual visitor, it is a lovely forest.

I grew up in the forests of New York and Ohio but I have been gone many years. It was a delight to see old friends such as jewelweed. I had a favorite leaning willow tree where as a preteen in upstate New York I sat and read. Jewelweed grew below it and hummingbirds would buzz in, pollinating the flowers.

pale touch-me-not, Impatiens pallida

Looking up the Minnesota plant, I discovered that there are two widespread eastern U.S. species: Impatiens capensis called jewelweed or spotted jewelweed and Impatiens pallida, called pale touch-me-not. Pale touch-me-not is yellow and has a downward pointing spur, while spotted jewelweed is very orange with very obvious spots and a c-shaped spur. I conclude the plant in the photo is not jewelweed from my childhood but its close relative, pale touch-me-not.

The name touch-me-not applies to a characteristic of both species: when the seeds are ripe, if you bump the seed pod, it snaps open and throws the seeds several feet from the plant. Of course that was one of my favorite characteristics of the plant: I loved pinching the seedpods to explode them. Alas I saw no ripe pods during the hike.

Another old friend along the trail was the common evening primrose, Oenothera biennis (evening primrose family Onagraceae). It is a widespread native biennial, a rosette of leaves the first year, a tall flowering stalk with big yellow flowers the second year. This one was close to five feet high.

common evening primrose, Oeothera biennis

Queen Ann's lace, Daucus carota, wild carrot, (dill family, Apiaceae) escaped from cultivation long ago and is growing very successfully as an eastern North American weed. I have lived west of where it can be found (California, Nebraska, Colorado) for the last 40 years, so I'm always pleased to see it and remember the smell from childhood rambles.

Queen Ann's lace, Daucus carota

Cup plants (Siphium perfoliatum, sunflower family, Asteraceae) are wonderful plants, but midwestern and not known to me as a child. The photo below has me, 5'3", for scale to show you how tall the cup plants are--the big leaves and yellow flowers behind me. They are tallgrass prairie plants, here growing in meadows in the forest. That is how high plants have to grow to compete effectively with the grasses in moist prairies.

cup plant, Silphium perfoliatum
with author for scale

Cup plant by itself

cup plant, Silphium perfoliatum

A destination of the hike was the karst cliffs, easily-eroded limestone layers from ancient seas, widespread in the region. Greatly aided by glacial runoff, water seeping into the karst formations created many large and small caves. (The Mystery Cave tour in the same state park explores one complex). Today, water still seeps in. In winter it freezes, making ice layers that are slow to melt in the spring. The effect really has to be experienced: air chilled from passing over the ice in the caves escapes from between rocks, creating spots that were easily ten degrees cooler than the surroundings. A botanical consequence of this phenomenon was the presence of northern plants, protected from the warming of the post-glacial period by this odd geology.

The rock walls and their pools were also very beautiful.

For contrast we climbed to the top of the hill (and mighty steep it was) coming out onto rocky hilltops which harbored small patches of prairie, protected from being overtaken by trees by the shallow rocky soil.

I particularly like milkweeds, so I noticed this one, the whorled milkweed, Asclepias verticillata (dogbane family, Apocynanceae)

whorled milkweed,
Asclepias verticillata

And there were all these cheerful coneflowers, the gray-headed coneflower or pinnate prairie coneflower, Ratibida pinnata (sunflower family, Asteraceae):

pinnate prairie coneflower, Ratibita pinnata

In general the hilltop was much warmer than under the trees and yet there were places where the cold air from the icy caves in the valley below came up, making peculiar cool spots. The views were great!

"See those other hills, the prairie vegetation is found there too,"
we say properly, carefully standing in the spot where the cold air
came up from the valley

Two more plants that were old friends:

Staghorn sumac, Rhus typhina, (cashew family, Anacardiaceae), a common shrub of the eastern half of the U.S.

staghorn sumac, Rhus typhina

and 

wild bergamot, Monarda fistulosa (mint family Lamiaceae). This is a native mint with a nice minty smell to the leaves and pretty flowers that attract bees and butterflies. (This is not the bergamot used in English breakfast tea. See post on bergamot).

wild bergamot, Monarda fistulosa

 A lovely park, wonderful hike and terrific plants.

Comments and corrections welcome

References
Moyle, J. B. and E. W. Moyle,. 2001. Northland Wildflowers. revised edition. University of Minnesota Press, Minneapolis Minnesota.
USDA Plants website http:/plants.usda.gov accessed 8/16/18

Related posts on this blog
Evening primroses--Names and Relations link
Evening primroses--Beautiful Wherever You Meet Them link
Milkweeds-- Just a Glimpse of Milkweed Diversity link

Kathy Keeler, A Wandering Botanist

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