They invade farmland, they cause cancer, and they may hold the key to the production of a host of futuristic synthetic products.

And for Professor of Biology Rolla M. Tryon and his wife, Lecturer in Biology Alice F. Tryon-two of the world's experts on the fern-individual research on the fuzzy, apparently harmless plant created a husband-wife team which has gone on to make pioneer advances in understanding the dual-natured fern.

While this mysterious plant may seem to inspire only nature lovers, the fern, which can grow virtually anywhere, is not only a key tool in basic science, but is rapidly gaining a foothold in areas ranging from industry to medicine.

Although studies of ferns began in the time of the Roman Empire, scientists still find the flowerless plant mysterious, and botanists like the Tryons are trying to solve puzzling questions about its highly unusual system of reproduction, its potential applications, and some of its devastating effects all over the globe.

Having devoted most of their lives to studying the plant, the Tryons have traced it to some of the globe's more exotic regions and in the process have classified and experimented with many of the estimated 15,000 types, ranging from the 80-foot-high fern tree to the "deadly" one-inch bracken.

"Their work is providing a critical, systematic framework for any subsequent research in the field, it's tremendously important for any other kind of studies," says Associate Professor of Biology Andrew H. Knoll.

As a graduate student at the University of Wisconsin. Alice Tryon recalls that one of her professors directed her toward research "counting the hairs on a maple leaf," which she says was "a real bore".

Hoping to pique her botanical interest, she approached Rolla Tryon, then a post-doctoral student, who advised her to study ferns instead.

At first she objected "because all ferns looked the same, but he helped me out a lot," she says. "I finished my thesis, and ten years later, he was still working on the same project," she adds.

After Alice got involved. I become more interested in it," Rolla Tryon jokes.

The two came to Harvard from Wisconsin in 1957, and both still teach courses in the Biology department.

Since they first arrived, fern studies have progressed in quantum leaps, and scientists have learned that the innocent-looking plant is not as harmless as it appears.

For example, recent studies have determined that one type of fern, bracken, a popular Japanese food, may cause stomach cancer.

Moreover, bracken has in several global regions devastated croplands and pastures, thereby endangering livestock that eat the fern. Yet even weed killing sprays can not eliminate the stubborn plant, and in Scotland alone, the bracken has monopolized more than 400,000 acres of cleared land.

"We've found something that kills it, but the problem is that it kills everything else as well." Alice Tryon says.

In a similar case land in Peru cleared for tea crops immediately fell victim to the green menace, Rolla Tryon says. During World War 11, he adds, the ubiquitous bracken quickly sprang up in bomb craters throughout England.

The force

Ferns, however, are not a purely dark force, the Tryons say.

For oilmen, they mean hefty savings in exploration costs, since fern fossils will indicate at what depths oil is likely to be found. Fern spores, very common in fossil records, are used to date the age of rocks below the earth's surface. Since scientists know that rocks of a certain age-or depth-are more likely to contain oil than others, fern-spore dating can help them decide whether to drill deeper to find the oil.

While ferns are a valuable asset to oilmen, coal producers use them to judge the quality of coal deposits.

Since a higher grade coal will contain different fern spores than a lower grade coal, identifying the type of spore will indicate to coalmen the quality of their deposit.

Fern leaves are even used in come areas to preserve cheese, and certain ferns have a medicinal use as diuretics.

The Tryon, however have found a more domestic purpose for the scientifically vital fern. In the spring they scan the New England woodlands for fiddlehead ferns, which the couple then eat fresh in soups and salads or freeze to enjoy year round.

One of Alice Tryon's favorite recipes, she says, is "fiddlehead ferns in cheese sauce," a recipe which she recently donated to a cookbook. "Cooking with a Harvard Accent"- a collection of recipes donated by members of the Harvard community.

On a more scientific level, Rollo Tryon's work concentrates on classifying various branches of the plant. Recently he and his wife completed the most comprehensive classification and analysis of the plant ever assembled. Other botanists have heralded the project-six years in the making and roughly 900 pages long-a scientific masterpiece.

"The book allows scientists to have unified concepts about the plant. It's a model that people in field aspire to," says Director of the Harvard University Herberia Donald H. Pfister.

While Rollo Tryon concentrates on the plant's visible characteristics, his wife concentrates on the tiny fern spores, on which she is a renowned expert. "I work on the little parts, while he does the big stuff," she says.

"It's not just postage stamp collecting." Knoll says, adding that "their work has had a critical impact in basic biology."

The pair also leads their Biology 247 class on an annual "class trip" to Mexico to give aspiring botanists hands-on experience with some of the tropical fern species.

In fact, the Tryons have tracked ferns all over the world, boasting of more than 20 international treks through Europe, Latin America and Africa.

While Rolla Tryon is the professor. Alice has not been content to play second fiddle. Aside from her pioneer work in fern-spore research, she has set precedents-initially by becoming the first woman member of New England's foremost association of botanists-the New England Botanists Club, then by becoming, in 1978, its first woman president.

In the 1960s, she was a leader in the drive to incorporate modern techniques in Harvard's biological studies, playing a key role in the University's acquisition of its first scanning electron microscope. The microscope has revolutionized several areas of study, including fern research.

"For the first time we're able really to see the stuff we're working with." Alice Tryon says.

Long before the modern surge of scientific interest in terns, these mysterious plants made their mark in the history of the Western world. For example, they were at one time considered a state-of the-art treatment for illnesses ranging from respiratory diseases to snake bites.

Historical records also show that for thousands of years people believed that, since ferns flowered but did not set visible seeds, they had supernatual powers. Even Shakespeare wrote that Oberon, King of the Fairies in A Midsummer's Night Dream, used these invisible seeds to make himself invisible and dealt harshly with those who wished to share his secret.

Eventually, a German bookseller unveiled the "seed mystery" when he discovered that the fern reproduces by means of a tiny, asexually generated spore which falls to the ground and then sprouts.

Using the electron microscope. Alice Tryon was the first scientist to discern the details of the size, shape and function of these spores. The spores, she explain, can take any number of forms, but the size and shape is crucial for survial, as some may need to travel great distances and others may need to hold water.

Despite new research by scientists like the Tryons, many of the fer's functions remain a riddle. For example, water must penetrate the spore wall for germination: and although scientists know it passes in, they are unsure of why it does not leave the spore in dry times.

Moreover, Mlicon and sporopollen in the walls of the spore must play some role in the plant's existence, but thus far no one has been able to explain what that roles is. In fact, the sporopollen is an unusually tough material scientists say, and although its chemical components are currently unknown, many feel it could be used to produce a host of durable synthetic products.

Studying ferns for many may seem like an insignificant cause Rollo Tryon disagrees: "If you want to make a meaningful contribution, you have to specailize in some small group. And that's just what we're doing".