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Discussion Starter #1 (Edited)
Credit goes to Cavan for the idea behind this thread. I was going to do it Monday or Tuesday, but after reading a few posts from people in northern climates that were sad about the lack of native aquatic plants in their areas, I felt compelled to bring them some happiness. :)

While working on my book, I realized that there were a lot of aquatic plant species that I had not seen before, and I ended up traveling all over Wisconsin to find them in their natural habitats. There are about 120 aquatic species in the Upper Midwest region, and many additional variations and subspecies. Here's a quick sample of the diversity we are blessed with in the Upper Midwest. This doesn't even scratch the surface of what can be seen in a day of traveling around a lake-rich region of Wisconsin. Some lakes will contain 40 or more species, but you have to be paying attention to see all of them, and of course have an idea of what you're looking for.

This is one of our Alisma species, which commonly occur in low spots that are periodically flooded. They will become more robust plants when the water recedes.


Azolla mexicana:
We have two Azolla spp. here, mostly in the Wolf and Missisippi River watersheds. Azolla floats around in quiet shallows with many species of Lemna, Spirodela, Riccia, Ricciocarpus, and Wolffia.


Brasenia schreberi:
This plant has a beautiful little flower that pops up in early July. It's often mistakenly called a water lily or pond lily, though it is actually in the Cabombaceae family, not the Nymphaceae like the lilies.


Callitriche palustris (C. verna):
We have three Callitriche spp., with C. palustris being the most common by far. C. heterophylla and C. hermaphroditica are quite rare. Callitriche tends to be found in quiet areas with groundwater seepage.


Mosses:
This is a Drepanoclatus moss, one of many mosses that occur submerged in Wisconsin lakes.


Eriocaulon aquaticum:
This is our only Eriocaulon, which prefers sandy substrates and softer water. Seen here with Elatine minima and Juncus pelocarpus.


Heteranthera dubia:
H. dubia occurs in lakes and rivers, and will occasionally flower, either when plants get stranded on mudflats, or when the plants grow densely together and can support the emergent flowers. Ranunculus aquatilis is also shown here.
 

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Discussion Starter #2 (Edited)
Duckweeds:
We have three species of Lemna, and three species of Wolffia in Wisconsin. Spirodela polyrhiza, Lemna minor, and Wolffia columbiana are shown here.


Ludwigia palustris:
This plant is very widespread, and can occur on shore or submerged. It is a very hardy species. Several other Ludwigia species occur in Wisconsin, many of them near water.


Myriophyllum:
This is Myriophyllum tenellum, our "dwarf water milfoil". Its leaves are reduced to tiny scales on the stem, but it does produce a spike of pink flowers like many of the other milfoils. We have eight watermilfoils in Wisconsin, with our most common of course being the invasive Eurasian watermilfoil, Myriophyllum spicatum.


Here is Myriophyllum verticillatum, commonly found in hard-water lakes and fens.


One of our showiest plants is the American lotus, Nelumbo lutea. This one is uncommon across the state, but usually abundant where it is found.


Water lilies:
This is our rarest water lily, Nuphar microphylla. It also hybridizes with Nuphar variegata, and shows intermediate characteristics.


Potamogeton:
We have 24 species of Potamogeton, plus many subspecies and varieties. Stuckenia and Zannichellia are often called "pondweeds" as well, but belong to their own groups. Potamogeton gramineus is shown, along with some Vallisneria americana and Najas flexilis.


Utricularia:
This is one of our eight Utricularia species, known as the bladderworts. They are all carnivorous species, some feeding on free-swimming organisms, others feeding on benthic organisms. Utricularia macrorhiza (a.k.a. U. vulgaris) flower shown with Brasenia schreberi.


And so concludes our brief tour of Wisconsin's aquatic flora. Despite our harsh climate, aquatic plants do just fine around here! I would encourage any Upper Midwest residents to become familiar with the differences in our native species, and get out there to see them!

Now for a quiz...who knows what this is? (scale in mm)

 

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Ah! I think I know what that last one is, but it escapes me. I'll think of it. A fruit, but of what?

Do you know anything about the jelly-like substance on the underside of Brasenia leaves and the petiole? Most curious. Its relationship to Cabomba makes a bit more sense if one has seen floating leaves of the latter.
 

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It's a coontail fruit! Looks like Ceratophyllum demersum, it should have more of a flange for C. echinatum. Very nice thread and shots. I may be up in Minnesota in the late spring for a meeting, I'll have to check out some wetlands. You guys get a lot of species we miss out on in the South.
 

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Discussion Starter #5
It is in fact a C. echinatum fruit. C. demersum's fruit has just three straight projections, instead of the many irregular projections on the C. echinatum fruits.

The gelatinous coating on the Brasenia stems and underside of leaves is an anti-predator defense mechanism (mostly anti-bacterial and anti-fungal). If you look at the top side of Brasenia leaves after they've been on the surface for a while, the slimy coating wears off and there is abundant evidence of insects and other organisms feeding on it. If you haven't gotten a chance to swim/snorkel through a patch of Brasenia stems, you should put that on your bucket list. :)
 

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Ah, gotcha. I read some papers on Ceratophyllum fruit morphology a few months ago, but I must have gotten them mixed up.
 

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Wow! I really appreciated this! This will be bookmarked for sure. I should go on a plant hunt once the ice goes away.
 

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Discussion Starter #9
I want that azolla! Thanks for the write-up! ^^
Azolla mexicana is a very pretty plant, but I think Ricciocarpus natans is still my favorite free-floating species. Probably because my wife and I spent hours hunched over blankets of duckweed in search of it!
 

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Eriocaulon aquaticum. Brings me back to a little hiking trip I did last year. I remember seeing a few but never bothered to grab any. Didn't have an emersed setup. Wish I could find some Azolla though. I'd rather that take over my tanks then duckweed.

Will post my own photos this spring when I go poking around again. Water is currently super cold. :^(

-Gordon
 

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Gets me interested in looking here in central West Virginia.

Are there any good sites for native plant identification?
 

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http://plants.ifas.ufl.edu/node/34 is a good start.

There are a number of aquatic plant manuals that you might be able to find at your library or possibly on Google Books. Fassett's A Manual of Aquatic Plants and Meunscher's Aquatic Plants of the United States are old but still good- you just have to be wary of taxonomy and nomenclature changes.

If you feel comfortable with more technical stuff, try some of the online keys like Weakley's flora and FNA.

The families are pretty easy to learn, and the genera for the most part are not too bad, though identifying to species can be very challenging in some of the bigger genera.
 

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Also, don't forget this site, here. We have some experts in plant identification who will usually get it right. Just send in a good picture.
 

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Discussion Starter #14
I use Crow & Hellquist's (Aquatic and Wetland Plants of Northeastern North America) and Gleason & Cronquist's Manual of Vascular Plants. Many people don't like using botanical keys and would prefer to see photographs, so that is where I stepped in.

I also reference Flora of North America online and the Freckmann Herbarium from UW-Stevens Point. The herbarium website offers a bunch of photographs for most of the Wisconsin flora, which are variable in quality.
 

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Have you ever encountered Ludwigia polycarpa? I'm eager to find that one.

It seems that many of these plants that do well in low nutrient conditions don't fare so well in many aquariums, which is a real shame. Gratiola aurea is a fascinating plant (supposedly grows in water up to 14ft deep!) but only seems to really thrive in mineralized soil tanks. Juncus pelocarpus will grow, but at an absolutely glacial pace. M. tenellum is fairly similar, though I'd like to try it from a different location that where we found it last. Elatine minima seems to always eventually rot from the bottom up, though I think that if you could keep it going long enough, you might be able to get some of it 'over the hump'.

Eriocaulon aquaticum differs drastically in terms of suitability from one location to the next; some stay pale and small while others are robust. That gives me hope for some of the others.
 

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Discussion Starter #16
I've only seen Ludwigia polycarpa once. It was growing on a very wet shoreline. It is apparently fairly common throughout the southern half of Wisconsin. I think I just haven't paid as much attention to the shoreline species as I have to the true aquatics. I intend to change that tendency this year though.

Eriocaulon aquaticum ranges from the size of a nickel to 4-5" in diameter around here. I've even seen it raise flowers above the surface in as much as 4ft of water. I couldn't believe my eyes when I saw such a miniscule plant in such nutrient-poor conditions producing a flower stalk that long.

I tried growing Elatine minima in a small pot on my windowsill, and it hung on for a few weeks but gave up. The Drosera rotundifolia and Drosera intermedia also didn't fare too well.
To my surprise, a couple of volunteers popped out of the same pot - Utricularia cornuta and Xyris torta - and flowered for me. Those species were a real treat to have sitting in my office.
 

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Discussion Starter #18
Wisconsin law prohibits removal of native aquatic vegetation unless it is by a shoreline property owner clearing/thinning their allowed 30ft "access corridor" in front of their property. It is also illegal to transport aquatic vegetation on a public roadway. Read over Wisconsin NR40 if you'd like to read about the specific statutes.

The exception to this is if you are collecting/transporting aquatic plants for identification purposes, or for disposal (in the case of unwanted exotic species).
 

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My only question is how do you make native plants safe to introduce into your tank without all kinds of organisms and possible pathogens etc.? Like in my Tanganyikan Rift Lake Tank, how can I just throw native plants in and not have the fish suffer because of it?
 

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Discussion Starter #20
There are rinsing products available that serve to remove or kill organisms that might be living on the plants. I haven't used them myself though, so I can't attest to their performance.

In my tanks, I try to replicate the native systems, so I just rinse them with water and whatever remains on the plants just lives in the tank. I only have a few native fish in my tanks, so I'm not too worried about pathogens and such.
 
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