The sedge above is Carex oklahomensis, Oklahoma Sedge, an endangered species in Indiana. It is somewhat similar to C. stipata, of which it has been treated as a variety in the past, but you'll notice that it doesn't have the spongy, inflated culm of C. stipata. Carex oklahomensis is found in wet meadows, marshes, and alluvial bottomlands, mostly in the plains and southern states. However, its range is thought to be increasing to the north and east. We saw this species in abundance in a wet sand flat.
Yes, it really does exist! Above is Carex lupuliformis, False Hop Sedge, a rare species in Indiana. While its range includes the entire eastern half of North America, it is said to be rare and local where it occurs. Until yesterday, anyone I had ever asked about this species said they had never seen it. You may think that this looks a lot like C. lupulina, the far more common and closely related hop sedge. The best way to tell the two apart is by looking at the achenes, which are longer than wide and not strongly knobbed on the angles in C. lupulina, but which are nearly as wide as long and strongly knobbed on the angles in C. lupuliformis.
Just look at those knobs! After seeing this, I was sure I'd never seen C. lupuliformis before, even though I had seen some plants with achenes that were weakly knobbed on the angles. Mike also pointed out a few additional characters to distinguish the two; C. lupuliformis usually has longer spikes, and the perigynia are usually more spreading than in C. lupulina.
As if seeing these two sedges hadn't already made my day, we also saw Carex crus-corvi, Ravenfoot Sedge, a plant I had only seen once before. Maybe the common name Ravenfoot Sedge makes sense to some, but I think it should be called Golf Tee Sedge.
Agree? These are the perigynia. Get a good look at those long, pointed beaks. The beaks of the perigynia are what make the inflorescence look so "spiky." Carex crus-corvi is found throughout most of the eastern half of the United States, as well as in Ontario, in habitats including wet meadows, marshes, swamps, and alluvial bottomlands.
I apologize that this photo isn't that great, but the culms of this species are shorter than the leaves and therefore the spikes are often somewhat hidden. This is Carex cumberlandensis, Cumberland Sedge. This beautiful sedge is found in mesic forests in the eastern half of the United States, but moreso in the southern portion of this range.
Southern Indiana is a world away from northern Indiana in terms of topography, geology and floral associations. I hope to get back more often in the future, as I rarely have the opportunity to botanize this scenic part of the state.