The Green Stuff in Swamps

While out saving the world from invasive species, I took a wrong turn and ended up finding myself at the edge of a small ash swamp that I could smell well before I got anywhere near it.  Covering the surface of the stagnant waters was a rather familiar sight, albeit one that most people think is algae or simple scum.

The scum, which is actually somewhat lovely in lighting conditions like this morning shot, is Lemna Minor, or duckweed.  It is native to both Europe and North America, and variants of it can be found throughout the rest of the northern hemisphere, preferring to grow in more temperate areas.  In Canada, it does not edge significantly into the boreal forest, though it can still grow fairly far north under ideal conditions.  In the United States, well, just take a look at the picture.  Further south than Michigan, especially along the slow-moving tributaries of the Mississippi and Ohio rivers, it forms an archetypal river scene of muddy, green waters lazily flowing under bald cypresses and water tupelos.  Here it completes a rather typical southeastern Michigan scene, shaded into a strange sort of green by towering ashes, cottonwoods, swamp oaks, and even aspen.

While it does have a tendency to completely take over the surface of a pond or other stagnant body of water, it is actually a rather natural part of the enclosed environments of such places, and is a valuable source of protein for animals that consume it, notably most kinds of waterfowl.  It has more protein than soybeans, and some parts of the world actually raise it commercially as a food crop.  To our manicured lawn mentality, it appears to be scum, as it no doubt did for generations of settlers who avoided swamps like the plague.  The ducks apparently disagree.