March 13th, 2011
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.
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.
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.
This is a Drepanoclatus moss, one of many mosses that occur submerged in Wisconsin lakes.
This is our only Eriocaulon, which prefers sandy substrates and softer water. Seen here with Elatine minima and Juncus pelocarpus.
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.
21 comments on "Live in a northern climate? Aquatic plants abound!"
We have three species of Lemna, and three species of Wolffia in Wisconsin. Spirodela polyrhiza, Lemna minor, and Wolffia columbiana are shown here.
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.
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.
This is our rarest water lily, Nuphar microphylla. It also hybridizes with Nuphar variegata, and shows intermediate characteristics.
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.
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)
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.
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.
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.
Ah, gotcha. I read some papers on Ceratophyllum fruit morphology a few months ago, but I must have gotten them mixed up.
I want that azolla! Thanks for the write-up! ^^
Wow! I really appreciated this! This will be bookmarked for sure. I should go on a plant hunt once the ice goes away.
Originally Posted by HolyAngelAzolla 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!
I want that azolla! Thanks for the write-up! ^^
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. :^(
Gets me interested in looking here in central West Virginia.
Are there any good sites for native plant identification?