TrevorStaker

It's almost certainly a member of the Rosaceae family, which includes your apples, cherries, ect., but I'm not positive if this is Crabapple or Hawthorn, from this picture. Check the tree for thorn or thorny structures. It can be hard to tell these two apart, because Crabapple (Pyrus coronaria) has false thorns, which are actually fruiting stems, and Hawthorn (Crataegus spp.) has true thorns. I think I see one of these "true" thorns in the picture, but I'm not sure. Hope I helped. :)

Oh, of course. From what I understand they can be planted nearby acidy waters, similar to our native willows, as they can clean the water up a little bit. Or at least thrive in it better than other things.

And for the record, I didn't really consider petroleum to be a nutrient. :)

Algae blooms are common in freshwater systems where an influx of nutrients, such as phosphorus and nitrogen, occur. Could something similar have happened down there?

Some parts of this plant are edible, actually. I've heard that they taste something like potatoes.

Oooh, this stuff is a nuisance. It's a very widespread invasive exotic, having a habit for choking out space for native shrubs and wildflowers. Many parks make an effort to clear it out from forests. What really makes it so volatile is that the fruit is eaten by songbirds and spread around like crazy.

Oh, dear! Well, looks like we've got ourselves a mystery on our hands.

Ah, yep, you got it Apryl! Magnolia grandiflora, an evergreen and, for Tennessee, a disjunct species. It's native to more southern parts of the eastern U.S. I'll add that to my list... :)
Great find!

I want to say American Holly, because I was just in Tennessee over the weekend and it was one of only a handful of trees that were green, but two things throw me off. The bark is the obvious one; holly bark that I've ever seen was always smooth, whereas this is platey and chippy. The other thing is the leaves, as holly almost always has leaves with sharp points on the ends. The other plant I remember with green leaves was the mountain laurel, but I'm pretty certain they don't get quite this big.

The final possibility that I can think of, barring species I'm unfamiliar with (a very very possible possibility!) would be that you didn't spot this February 22nd. Is there any further info you could provide us with? :)

Looks a little bit like water hemlock, but the leaves don't looks right for that species...

A possibility that comes to mind would be a hydrangea, but I'm not certain on it.

Either way, great picture!