Window on Nature
By Lowell & Kaye Christie, F47246
Most plants make their own food from sunlight and carbon dioxide, but a few do it in other ways. They may parasitize other plants or dine on decaying plant and animal material found in the soil; some use a combination of both methods. We’re all familiar with the parasitic plant called mistletoe. The popular holiday decoration advertises its presence in trees by its size and clumping habit. Other plants catch insect prey for food, but we’ve given them due consideration in a previous column.
Saprophytes, on the other hand, are less familiar. The name comes from the Greek words sapros, meaning rotten, and phyte, meaning plant. Such oddities of the plant kingdom are few in number, but they’re so striking that you’ll certainly remember their appearance once you see them.
(Indian pipes Monotropa uniflora) are probably the best known of North America’s saprophytes. These plants are a ghostly white color and nearly leafless. Each individual plant produces one five-petal flower that faces downward. During its early development, the shape of the plant resembles that of a clay pipe whose stem has been stuck in the earth, thus the name Indian pipe. When mature, the flower turns upward.
Like some mushrooms, an Indian pipe plant can’t be gathered successfully. Its flesh turns black when cut or even bruised, and the stem oozes a clear, gelatinous substance. It’s no surprise to learn that other names given to the plant include ghost flower, corpse plant, and fairy smoke.
The plant also has been used for medicinal purposes. American Indians used the plant as an eye lotion, thus it became called eyebright. During the 19th century, Indian pipe was used to treat spasms, fainting spells, and nervous conditions, and thus acquired the names convulsion root, fitroot, and convulsion weed.
Indian pipes historically have been considered saprophytes because their primary food source was thought to be dead and decaying plant roots. More recent research, however, indicates that the connection is assisted by a special type of fungus, mycorrhizae, that penetrates nearby living tree roots and permits Indian pipes to get an easier meal. Should the majority of nutrients come through living roots, the plant would be more accurately designated “hemiparasitic” (partially parasitic) instead of just saprophytic. The appetite of the Indian pipe is much too small to harm huge trees.
Indian pipe is widely found in North America. Given the right conditions of full or partial shade within a forest, Indian pipe can be found in North America from the Atlantic Ocean to the Pacific Ocean, and from Canada and Alaska south into Mexico.
(The pinedrop Pterospora andromeda) may be genetically similar to Indian pipe, but it’s quite different in appearance. This plant has numerous small flowers — they grow in clusters — rather than the one large one, and its color ranges from amber to orange. Pinedrops got their name from the fact that they grow at the base of pine and fir trees. Like Indian pipes, pinedrops are both parasitic and saprophytic, and they both associate with the same kind of mycorrhizae fungus.
Snow plant (Sarcodes sanguinea) appears in a far more limited range than Indian pipe, but it is, hands down, the most spectacular of the saprophytes we’ve seen. There’s nothing drab about this plant; it’s bright red!
The plant’s blooming schedule insures additional drama, since, as the name implies, it flowers in early spring, just as the snow is melting. It was our good fortune to view the plant in the Cascade Mountains of Washington. We could hardly miss noticing it poking its bright red head above the snow. Unlike its Indian pipe cousin, snow plant erupts in clusters of up to a dozen flowers, with some standing as much as a foot tall. We were so taken by finding such an exquisite plant in such unlikely surroundings that we stared at it long enough for a passerby to think we were watching the snow melt.
These aren’t the only saprophytic/parasitic plants; a couple of members of the orchid family are included also — coral roots and phantom orchids. But we have to leave time to consider the most common of this group, dodder (Cuscata).
We saw dodder first as kids — Lowell growing up in California and Kaye growing up in Nebraska. Just about anyone from a rural or small town region south of Canada has probably spotted this strange plant while driving or riding along the roadways. In our experience, it’s especially common in the Great Plains region, and you don’t need to look for it around trees. Full sun is just fine for dodder, especially if it’s full sun in an alfalfa field.
Generally speaking, dodder is a twining yellow or orange plant that looks like a drift of color as it winds around other plants or on the ground. One particularly dramatic dodder species has stems so thin and threadlike that you might think of attacking it with knitting needles or a crochet hook. It appears as though a cat had busily spread a tangled mass of strands over the ground.
Dodder can strangle the plants it feeds on and is responsible for spreading certain types of plant diseases. Dodder also can be commercially troublesome where fields of alfalfa, clover, and onion are grown for seed. Where dodder has invaded, its abundant seeds are difficult to separate from the seed crop. No farmer wants an annual battle with dodder seeds in the seed bin.
Dodder flowers become numerous from early June and continue blooming to the end of the growing season. The white, pink, or yellow blossoms grow in tight balls or in a loose cluster. Seed that drops to the ground germinates the following year.
Other names for this parasite are love vine and goldthread, as well as less complimentary monikers such as strangleweed, devil’s guts, and devil’s hair.