Friday, October 09, 2009

Miller Beach Pannes

Last week, I got the chance to explore the pannes at Miller Beach in Gary, IN with Nick Gressick, another botanist with JFNew. Swink and Wilhelm define a panne as a typically moist interdunal depression in calcareous sands on the lee sides of dunes near Lake Michigan - the vegetation quite fen-like in composition. There was a lot that I was familiar with in the pannes, and a lot that was new.
The pannes seem like quite the place for orchids. Spiranthes orchids were all over the place. Spiranthes cernua and Spiranthes magnicamporum are both blooming in the area right now. The two can be difficult to distinguish. One of the key characteristics of S. magnicamporum are upward arching lateral sepals, which these seem to have. According to Mike Homoya, "To be absolutely sure of the identity, an inspection of the seeds is needed. Spiranthes magnicamporum has monoembryonic seeds and S. cernua has polyembryonic seeds." I guess I will live with a little uncertainty. As far as other orchids go, we saw the fruiting remains of Liparis loeselii, Pogonia ophioglossoides, and what looked like a Platanthera.

It seems like I am always trying to get a good picture of Agalinis purpurea. It is at Cabin Creek Bog, but I haven't felt like I have captured it well. It was very common in the pannes. One of the dominant shrubs in the pannes was a plant I was not familiar with. Kalm's St. John's Wort (Hypericum kalmainum) was growing thickly with Cornus sericea and Dasiphora fruticosa. I would like to see it in bloom. Swink and Welhelm do a very good job discribing the panne community we observed, listing some of the associates for H. kalmainum as Aster dumosus, Cladium mariscoides, Lobelia kamii, Sabatia angularis, Scleria verticillata, and Triglochin maritima.

Gentiana crinita - the much loved and photographed Fringed Gentian.


Anonymous said...

I was looking for the name of Spiranthes orchids by searching pictures and found your site. We have a large number of these growing in Chicago on a beach nature area in the middle of the city. It is 11 acre area with amazing plant and animal life right in the city. It is officially called The Montrose Dunes. Montrose is a near by street and although they do not compare with the Indiana dunes there are dunes as well as a recognized panne area. If you are ever in the city come and check it out.

ben said...

Thanks for the comment. I have been to Montrose park to look for birds before, but I didn't know they had Spiranthes. I'll have to look next time.