We first visited Prairie Creek Barrens in Daviess County, a preserve where the observation of a few remnant rare species prompted the radical restoration act of scraping the sandy substrate to remove River Birch (Betula nigra) that had invaded the site as a result of natural succession. This natural invasion had led to a mostly nonexistent understory. Removing the River Birch and scaping the soil may seem like an extreme form of restoration, but at this site it has led to the restoration of a rich and conservative flora from the buried seed bank.
The photograph below shows the portion of the site where restoration has taken place. It is difficult to see the variety of species present in this photo, so I will highlight some of them below.
Click here for an interesting write-up on Isoetes at The Vasculum.
A large population of Creeping St. Johnswort (Hypericum adpressum) is present in both the scraped and unscraped areas of the site. This St. Johnswort can look similar to several other species in the genus, but the plant is not woody and the leaves and sepals are revolute-margined (the margins are rolled under). This is an endangered species in several states, including Indiana, where it is only known from 2 or 3 counties. It is found most commonly on pond shores and in wet, sandy soil.
One of the plants that Mike told me we might see was Axilflower (Mecardonia acuminata). Say what? I had never heard of this Scroph, which can be found in the southern United States from Kansas to Texas and east. Looking at photos online, I thought it may look like a hedgehyssop (Gratiola) or a false pimpernel (Lindernia), but after seeing it first hand I don't think I could ever mistake it for anything else. Unfortunately, it was not yet in flower, but it certainly is still an interesting little plant. Axilflower can be found in a range of habitats, including swamps, floodplains, flatwoods, alluvial woods, savannas, bogs, and marshes.
Surrounding the wetland portion of the preserve are rolling windblown sandhills on which prairie restoration is taking place. But this isn't your typical prairie restoration (planting) full of dense Big Bluestem (Andropogon gerardii), Little Bluestem (Schizachyrium scoparium), Indian Grass (Sorghastrum nutans) and Switch Grass (Panicum virgatum). At this site, care has been taken to collect seed mostly locally and to choose species that occurred in this area based on presettlement notes and records from Charles Deam.
Fringeleaf Wild Petunia (Ruellia humilis) is one of the more attractive species growing in the prairie restoration. This species is similar to the Limestone Wild Petunia discussed in my recent post on Loblolly Marsh; both are way more attractive than the annual petunias used in landscaping. I don't see wild petunias very often in the Chicago Region, so it was really a treat to see both species within a week. Fringeleaf Wild Petunia grows in prairies, open woodlands, limestone glades, and sandy areas.
The plant species that the insects seemed to find most attractive was Narrowleaf Mountainmint (Pycnanthemum tenuifolium). If you click on the photo to enlarge it, you will probably be able to find at least three insects; there were probably 10 or more insects easily visible on the plant when I first saw it. Narrowleaf Mountainmint is similar to Virginia Mountainmint (Pycnanthemum virginianum), but the leaves of Narrowleaf Mountainmint are narrower and have only a faint odor when crushed, and the stems are completely hairless. In Virginia Mountainmint, the leaves are wider and very fragrant when crushed, and the four angles of the stem are pubescent. This is a species of prairies.
A common but still interesting plant that we observed at the site was the prairie species Purple Milkwort (Polygala sanguinea). What is shown below is a raceme composed of many flowers. An individual flower is made up of two enlarged pinkish-purple sepals (commonly referred to in the genus Polygala as "wings"), three very small sepals, and a tube of three small petals, one with a crest at the tip.
After Prairie Creek Barrens, we visited Plaster Creek Seeps Nature Preserve, a Forest Service and TNC property in Martin County, Indiana. Here we saw plant communities unlike any I had seen in Indiana previously. One of those communities was the sandstone glade.
Notice the small, gnarled trees and the exposed sandstone substrate in the photo above. On other portions of the glade, mosses dominated. I don't claim to know mosses, but I think the moss in the photo below may be a Leucobryum. Hopefully someone will correct me if I'm wrong.
Two oak species found in the sandstone glades of southern Indiana but not found in the northern part of the state are Chestnut Oak (Quercus prinus) and Blackjack Oak (Quercus marilandica).
Leaves of Chestnut Oak are shown above, and those of Blackjack Oak are below.
There weren't a lot of plants flowering in the sandstone glade community. One of the herbaceous plants we found was Narrowleaf Pinweed (Lechea tenuifolia). This species can also be found growing on sand in Black Oak savannas in northwest Indiana.
After spending some time on the glade, we descended to the sandstone ledges. Water was seeping out from spots along the ledges, and was likely dripping from the ledges earlier in the year. It was very interesting to see Sphagnum Moss (Sphagnum sp.), a species typically associated with bogs, growing on these ledges. I had seen this earlier in the year when in Georgia as well. The presence of Sphagnum on a sandstone ledge creates a very unique and interesting plant community.
Also growing on the ledges was what we believe to be Rock Clubmoss (Huperzia porophila). This species is known from much of eastern North America, but it seems to be rather uncommon in every state and province that it is known. Rock Clubmoss grows on damp, shaded, acidic sandstone. Rock Clubmoss is similar to Shining Clubmoss (Huperzia lucidula), but can be distinguished by leaf shape and number of teeth on the leaves (obovate with 1 to 8 irregular teeth in Shining Clubmoss; lanceolate with up to 3 low teeth in Rock Clubmoss).
After examining the ledges, we followed the seeping water into the sandstone seep. This community was very interesting and consisted mostly of species I am familiar with from acidic woods in northern Indiana, including Cinnamon Fern (Osmunda cinnamomea), Royal Fern (Osmunda regalis v. spectabilis), and Brome-like Sedge (Carex bromoides).
Another interesting plant common in the sandstone seep was Lizard's Tail (Saururus cernuus). Isn't that Latin name just about the funnest thing you've ever said? Lizard's Tail is found throughout much of eastern North America, often in swampy woods and other wet soil. As the inflorescence matures, it will droop, which is why the specific epithet is "cernuus" (cernuus = nodding).
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By this point, we were thoroughly exhausted, in part from the heat and humidity, and in part from the steep and difficult terrain (for Indiana, that is), so we called it a day. I vowed to try to get back to southern Indiana at least once a year to continue to learn about the unique natural communities present just a few hours from home.