September 2016

"Ghosts" in Iowa Woodlands

Marla Mertz, Naturalist, Marion County Conservation

Venturing into the woods in late summer is not common for me, as the prairie whispers my name. A quick walk in the woods might just be a good change of pace. Hiking boots on and a camera over my shoulder, off to the woods I go. Within a few short feet of a walking trail, my eyes immediately zoomed to the ground...a snow white flower? mushroom? fungus? Kneeling to take a closer look, the flower appeared to be a fungus. My eyes gaze around the forest floor to see a few tinier, white looking, flowers and some have tinges of color. Flower or fungus? Being easily entertained, I photographed in every way shape and form in hopes that some would help me to define this unique “something.”

What appeared to be a strange looking fungus, had all of the aspects of a true flower. Not green, but white; a clammy feeling to the touch and waxy petal-looking leaves that alternate up the stem. Some were in clumps and some were singled out. Some bowed and some stood straight up. Some had a pink tinge of color and some had a dark purple to black tinge around the petal looking leaves. Some had little yellow-looking flowers within the top of the plant. After an hour of photographing and then digging out the “old reliables” of resource books, all of these observations pointed in the direction of the ‘ghost plant,’ also known as Indian pipe and fairy smoke.

Mystery solved… almost! How can it be a true flower if it lacks chlorophyll? Chlorophyll is necessary for photosynthesis, where most plants are able to manufacture their own food from nutrients in the soil, carbon dioxide, and with the presence of sunlight and water. Without chlorophyll, the Indian pipe does not produce its own food, so there is no need for leaves along the stem. Instead of leaves, there are small scales, alternating up the stem. Since it does not need the presence of sunlight, it can grow in the darkest areas of a woodland where buried tree roots, leaves, and other organic matter can be found.

So how does the plant receive food? Indian pipe has roots and searches out a fungus within the soil where it grows, called a mycorrhizal fungus. This fungus and Indian pipe form a connection and the nearby trees seem to transfer nutrients through the fungus to the Indian pipe. Among botanists, there is still not agreement on whether the Indian pipe roots get nutrients directly or indirectly through the fungi.

The flower of Indian pipe is borne at the top of the stem, first drooping to form the shape of a “pipe.” Once pollinated, the flower turns upright and the plant seems to turn a blackish brown color. The fruit is almost the shape of an urn or vase and appears to look like a seed capsule with five cells. Each cell contains many seeds and, once again, must rely on the fungus to obtain the necessary nutrients it needs to grow. The pollinators of Indian pipe seem to be bees and small skipper butterflies, but not all the questions of this unusual herbaceous plant have been answered. In looking at each individual plant, all characteristics are obvious, but looking more closely, you may find many of last year’s remnants shadowing within the new grouping of clustered pipes.

For more information, see Wildflowers of Iowa Woodlands, Sylvan T. Runkel and Alvin F. Bull

Click here for Indian pipe photo album in Google Photos.