Speaking of Nature: One killer plant: Discover the deadly beauty of the Northern pitcher plant

This week I shift my focus away from lakes and pond and toward bogs. There is certainly some overlap between these two habitats, but if you are able to find yourself in a majority-bog ecosystem, then you will see some very interesting things. I took today’s photo while visiting a place called Quoddy Head State Park, in Maine, but there are opportunities to find similar conditions right here in western Massachusetts. More on that later.

A bog is defined as, “a type of wetland characterized by acidic, spongy, and poorly drained peat-rich soil. Bogs are typically formed from decaying vegetation, primarily sphagnum moss, and are often found in cool, northern climates. They are distinct from marshes and swamps due to their low mineral content, primarily relying on rainwater for their water source.” There is a lot to unpack in this definition, but I hope you will agree that we needn’t go too deep into the terminology. So, for the sake of simplicity, let’s just focus on the part that says, “low mineral content.”

In higher altitudes of the Northeast, where the growing season is short and temperatures are relatively low, conditions specific to certain landscape configurations can result in perfect conditions for a bog to form. This is typically going to happen in a place where a basin, surrounded by high ground, will collect rainwater but receive little to no additional water from a stream. The water pools and if Sphagnum moss (there are 360 species of mosses in the Sphagnum genus) is present, the moss can start to create acidic conditions in the water by absorbing calcium and potassium ions and releasing hydrogen ions.

This, in turn, will create a substrate that has plenty of water, but very limited amounts of other nutrients required by plants. Photosynthesis allows plants to make glucose from water and carbon dioxide, but it does not allow plants to manufacture other nutrients that are integral in the production of nucleic acids, proteins, and lipids. Thus, a plant growing in an area dominated by Sphagnum is going to have to find another source for these nutrients.

For some species, the answer is to kill and digest animals; packages that are bursting with nutrients. But how does a plant capture and kill an animal? Well, there are many methods of doing this and the one that I am going to focus on today is rather simple: lure in an insect and drown it. The plant that performs this little trick is the Northern pitcher plant (Sarracenia purpurea) and it relies on its highly modified leaves to pull it off.

A single leaf from a pitcher plant forms a hollow tube with a narrow opening at the top and a swollen chamber in the middle. This chamber fills with water and this is where the plant will kill its prey.

Above the narrow opening of the leaf there is a specialized structure called a “lid,” so named because in some species the structure is positioned horizontally above the pitcher. The lid is decorated with stripes, dotted with structures that produce nectar, and covered with downward-pointing “hairs.” This is the part of the plant that lures in its victims.

Once a fly, hornet, bee, spider, or moth lands on the lid, the hairs make moving upwards difficult, so the insect will tend to move down toward the “mouth” of the pitcher. Here, there are specialized epithelial cells that are waxy, slippery and easily shed by the plant. Imagine walking across a floor covered with Post-It notes and you’ll get the idea. The more the insect walks, the more of these sticky cells accumulate and the more difficult it becomes to “hold on.”

Eventually, such an insect will slip and fall into the pitcher itself and for most that means the game is over. New pitcher plant leaves can fill the water with digestive enzymes that will disassemble the prey into its organic components. Older leaves can still absorb nutrients, but they rely on a microscopic ecosystem of microorganisms to do the digesting for them. There is also a very specialized species of mosquito (the pitcher plant mosquito Wyeomyia smithii) and a midge (the pitcher plant midge Metriocnemus knabi) that have evolved to live in the water inside a pitcher plant’s leaves. Both of these insects feed on the drown insects and release nutrients in their wastes.

So, where can you go to see one of these amazing plants for yourself? Well, as luck would have it I have personal experience with two wonderful spots here in western Massachusetts. The first is a Nature Conservancy property known as Hawley Bog. Rather than get bogged down with directions (see what I did there?) I will just suggest that you type it into a search engine and then use a map program to take you to your destination. Hawley Bog is an amazing place where you will be able to walk out onto a floating peat mat and find pitcher plants easily.

The other location is Savoy Mountain State Forest. There are three locations where I know that pitcher plants can be found at Savoy Mountain. One is a bog area next to the Spruce Hill trail and can easily be seen on the west side of Central Shaft Road. The second location is South Pond, which is accessible through the campground. The third location is Bog Pond, where you can actually get a canoe into the water and go exploring. Just look for the dark red leaves of the pitcher plant and you should find them relatively easily. Wherever you go for a visit, I hope you have a great time.

Bill Danielson has been a professional writer and nature photographer for 28 years. He has worked for the National Park Service, the US Forest Service, the Nature Conservancy and the Massachusetts State Parks and he currently teaches high school biology and physics. For more information visit his website at www.speakingofnature.com, or go to Speaking of Nature on Facebook.