While considered an herb, the Indian Pipe (Monotropa uniflora) is not green, but rather a translucent white plant that grows as a clump of stalks averaging seven inches high, which have scales on the stem and flowery heads drooping at the top. The flowers bear a small fruit that has very small seeds.
The plant’s color can vary from white, to pinkish, to white with black spots. An herb that closely resembles the Indian Pipe is the reddish-colored Pinesap (Monotropa hypopitys), sometimes called “Dutchman’s Pipe.”
Indian Pipes Don’t Manufacture Food by Photosynthesis
The Indian Pipe, also known as “Corpse Plant,” “Ghost Flower,” or “Fits Root,” is found across North America in shady woodland areas and temperate Asia, Central and South America. In the U.S. it can be found from mid-summer to early fall, as the warmer months produce the right conditions of moisture and temperature necessary for growth.
Unlike green plants, which contain chlorophyll to aid in the process of photosynthesis—the use of sunlight to convert carbon dioxide and water to carbohydrates, which feed the plant—the Indian Pipe does not contain chlorophyll. It turns from its waxy, white form to black when it is picked, damaged or dried out. Because it does not rely on photosynthesis, the Indian Pipe can grow in very dark conditions.
This Plant Was Once Known as a Saprophyte
The Indian Pipe was once thought to be a “saprophyte”—a plant that obtains its nutrients from decaying organic matter on the forest floor. Mushrooms, and some mosses and ferns have been called saprophytes. According to Carol Gracie, who wrote the article “Indian Pipe—Summer Ghost of the Forest” for the Bedford, New York, Audubon Society's web site, the term “saprophyte” is obsolete.
This is because plants such as the Indian Pipe use an intermediary—small fungi—to obtain nutrients from nearby tree roots. The relationship a fungus has with the roots of a seed plant is called “mycorrhiza” (hence the term mycorrhizal fungi). The Indian Pipe seems to be “parasitic on the fungi, as no benefit to the fungus from its association with the Indian Pipe has been discerned,” Gracie writes. She states that experiments have shown that marked carbon and phosphorus injected into trees were taken up by the Indian Pipes, proving the fungus was the transfer point.
A Plant Reclassified Into the Family Ericaceae
Additionally, the Indian Pipe was originally classified into the family Monotropaceae, but after further research was reclassified to be included in the Ericaceae family of plants (heaths). Heaths are herbs, shrubs and trees that thrive in acidic soil, like cranberry, blueberry, azalea and rhododendron, and are known to have the same kind of relationship with mychorrhizal fungi.
An Angiosperm Whose Seeds Are Encased in the Fruit
A flowering plant like the Indian Pipe is called an angiosperm, and it is of the type where the seeds are enclosed in a fruit. The flower of the Indian Pipe turns upward after pollination, and then the fruit continues to develop until fall. The fruits attract wildlife that assists in seed-dispersal.
The story of this unusual plant is one that shows how science reveals the mysteries of some plants over time, and that we must often revise what we have learned to see how new details change our larger view of the natural world.
Sources:
- Gracie, Carol. “Indian Pipe—Summer Ghost of the Forest.” Bedford Audubon Society. Accessed 21 July 2009. <www.bedfordaudubon.org/seasons/summer/indian_pipe01.html>
- “Indian Pipe.” The New Encyclopedia Britannica, 15th ed., Vol. 6. Chicago: Encyclopedia Britannica, Inc., 2007.
- Wernert, Susan J., Ed. “Indian Pipe.” Reader’s Digest North American Wildlife. Pleasantville: The Reader’s Digest Association, Inc., 1982.
