Dive deep into the unseen, three-way relationship between the mysterious ghost pipe, fungi and forest trees.
By Sara Wright
Ghost pipe, Indian pipe, and ice plant are three common names for Monotropa uniflora, a plant that totally lacks chlorophyll, making this group an exception in the plant world.
I loved ghost pipes as a child, fascinated by the ‘bouquets’ of pure white nodding flowers, one on each stalk, and the diminutive white ‘leaves’ (actually scales) that my little brother and I found in the deep, shaded woods. Frequently, they appeared after a good rain. Because my brother and I haunted our woods, we noted how fast the flowers turned their faces to the sky and how soon the plants turned blackish. The whole show was over in a few days. I have since learned that, as soon as the flowers turn skyward, they have been pollinated by bumblebees or other insects who crawled into the flowers. The seeds are released to the wind.
Ghost pipe is low growing, about four to ten inches tall. Some are pale pink with spots. Sometimes only one or two single stemmed flowers appear, but I have large clumps of white ghost pipes just about everywhere. The delicate four to six petals of the flower begin to bloom around the end of June, but it isn’t until later in the summer that I find clusters in abundance. This year I had many groups late into September.
Although ghost pipes are native throughout most of the United States and grow in Mexico, Central America, and Asia, they are considered endangered in a number of states. They will not grow in recently disturbed areas. An inventory of plants taken a decade after either clear cut or selective logging operations demonstrates the dramatic decline of ghost pipe in states where the plant has been studied. Many states including Maine haven’t even addressed the prevalence or scarcity of ghost pipes, so their status is unknown. The International Union for Conservation and Biodiversity (ICUN) has just started to study fungi on a global level so only a few fungi are listed as endangered. The lack of data is troubling.
What we do know is that this plant has highly specialized growing conditions. It cannot be grown at home or commercially, and the deep rich forests that ghost pipes depend on for survival are in decline as a direct result of clear cut or ‘selective’ logging (taking only the most economically valuable trees), invasive plant infestations, human development, etc. The current trend of using the forest to forage for ‘free’ food and medicines without restraint may be the worst threat the ghost pipe has ever faced. I saw baskets of ghost pipes on a mushroom website last summer. It is important to note that these plants are perennials, and, if the roots, more accurately hyphae, are pulled, the plant will not return. One caveat: the plant’s toxicity may be a potential issue for some people.
I first became curious about ghost pipe’s fungal relationships after my recent re-reading of Merlin Sheldrake’s Entangled Life because Voyria, a flower that he studied in Panama, is also a non-photosynthetic native flowering plant. Like ghost pipe, Voyria obtains its nutrients by tapping into tree roots that obtain energy from photosynthesis, but it does so indirectly. Ghost pipes do exactly the same thing. They use the root-like structures of mycelia of some Russulas, the fruiting bodies of the mycorrhizal mycelial network, as their highway to reach the roots of trees. Russula are a very large genus of mushrooms that are composed of many species that include Lactarius and Amanitas.
Unlike other mycorrhizal fungi that penetrate the roots, the hyphae of these fungi do not penetrate their host’s cell walls. Instead, they form a mantle of intricately branched hyphae between the root cells of trees and take what they need that way (ectomycorrhizal). They grow profusely under hemlock, pine, fir, spruce, oak, hickory, alder, and beech if the right fungi are there!
To my great surprise, I finally have an answer to a question I have had for years. Across the brook where I live I have an older mixed conifer forest that has a large healthy stand of hemlock. I find so many Amanitas, Russulas, and Lactarius mushrooms in these areas that are peppered with generous sprays of ghost pipes that it has been impossible to ignore that there had to be a reason I had such abundance in this part of my woods. The mycelial network that supports Russulas, Lactarius, and Amanitas acts as the intermediate “highway” connecting ghost pipes to the tree roots that will provide them with the nutrients they need for survival. Discovering this fantastic relationship between ghost pipes, Russulas, and hemlocks leaves me with more questions than answers. I find this three-way highway to be an extraordinary adaptation. What is it about a particular fungus that makes it so appealing as an intermediate host?
Equally mind-bending is the fact that ghost pipe and Voyria are only two of approximately 3,000 non-photosynthetic plants. I had no idea there were so many. It’s abundantly clear to me that I know almost nothing about what’s happening right under my feet! Enjoy these astonishing plants if you walk in densely shaded protected woods and go back more than once to see what happens in one day! But please do not pick or harvest the stems and flowers.