Papyrus, the marsh-dwelling wonder plant of ancient Egypt that later vanished from the region, is making a comeback. From cuttings carefully nurtured in large pots set in the Nile River in Cairo, the reedy plant once worshiped by pharaohs has become a major tourist attraction and is reviving interest in one of history's most important plant-human relationships. Papyrus provided ancient peoples with the first useful form of writing paper. It also is the plant that provided early settlers in the cradle of civilization with raw materials to make sandals, twine, mats, cloth, building material and fuel. And, according to Hassan Ragab, head of Cairo's Papyrus Institute, which has fostered much of the revived interest in it, the plant's thick rootstock, or rhizome, provided ancient Egyptians an important source of calorie-rich food. Papyrus did even more for cultures that flourished along the Nile. Its reeds were bundled to make boats and, as suggested by a scene depicted in an ancient temple, it was made into life preservers. In the temple, a bas relief shows a boatman rowing a papyrus boat and wearing a bulky collar made from a bundle of the plant's dried stems. Today, Ethiopians build small papyrus boats as they have for thousands of years on the shores of Lake Tana. This is the same natural material that Thor Heyerdahl used to build a boat, Ra II, in which he crossed the Atlantic from Africa to the West Indies in 1970. The wonders of papyrus were well understood in antiquity. Pliny the Elder, a Roman writer of the 1st century A.D., called it "the material on which the immortality of human beings depends . . . ." The constitution of Athens was written on papyrus paper. Woven into crowns, its delicate flowers adorned Roman religious shrines and the heads of diplomats. Bouquets of papyrus flowers were left in Egyptian tombs to honor the dead, an antecedent of today's tradition of floral tributes at funerals. Papyrus also helped the pharoahs to build armies. Exports of Egyptian-made papyrus paper beginning about 3000 B.C. raised money needed to maintain armies on the Nile. On the strength of its armed forces, Egypt extended its rule over Nubia to the south and by 1400 B.C., had pushed its northeastern border across Phoenicia to the Euphrates River. In later millennia, papyrus exports from government-controlled marshes would become the chief source of income for Egyptian monarchs. Other nations also benefited militarily from papyrus. In the 5th century B.C., Xerxes, king of Persia, used papyrus stems to construct a bridge of boats across the Hellespont (now the Dardanelles), enabling his army to invade Europe. But the plant's most important role was for paper. It was sold in large bales or rolls sometimes 20 to 45 yards long. Factories that produced it must have been large by the standards of those times. To protect their monopoly, pharaohs jealously guarded details of the papermaking process. It remained a secret for centuries until Pliny the Elder revealed it in 77 A.D. Many small businesses making papyrus paper in Cairo today use this technique, steps of which are explained at the far right of this page. In ancient times, papyrus paper was recycled. After the writing on it no longer was needed, old papyrus was sold for use as mummy wrappings and to make a kind of pasteboard used to manufacture coffins. Papyrus paper-making waned in the 9th century A.D., when Egypt came under Arab rule. The Arabs had learned another technique for making paper by using linen fiber from the flax plant. That technique had been developed in China about 100 A.D. Papyrus markets also suffered as use of parchment, made from animal skins, became popular in ancient Rome. During the 9th century, papyrus went into severe decline, and linen dominated the paper market until being replaced in the 19th century by cellulose from wood pulp. Once the secret of making papyrus paper was revealed, other cultures adopted it. According to some sources, early popes, who used papyrus paper to record major pronouncements, tried to secure a cheap supply by having cuttings of the plant smuggled into Sicily. Once established there, it was used to manufacture Italian papyrus paper. The plant still grows there in the bright blue waters near Siracusa, where it supplies a modest souvenir papyrus paper industry. Papyrus paper was used to record early versions of the Bible but not in the continuous scroll form favored by others. Early Christians cut short lengths from a papyrus roll and stacked them to make a book, or codex, as it was known. The innovation made for a more convenient document. So important was papyrus in ancient Egyptian culture that representations of it in painting, sculpture and even architectural designs were common. For example, it often was included in scenery on wall paintings in tombs because it symbolized the greenness and prosperity of the Nile Delta. Because of this association, simple hieroglyphs showing papyrus plants growing in water represented the verb "to prosper." During Egypt's Old Kingdom period (2700-2200 B.C.), papyrus stalks were used in religious ceremonies and were presented to Hathor, goddess of love and joy. Papyrus scepters were presented to other gods in search of favors. The close relationship that developed between people and plant also had significant effects on art and architecture. The form of the plant lent itself as a model for design, so the papyrus motif was commonly incorporated into amulets, mirror handles and other objects. It also seems to have been an inspiration for design of free-standing columns. In the first known temple columns, built as reliefs in Zoser's temple and pyramid complex in Saqqara in 2686 B.C., architects created columns shaped like a stylized papyrus stem topped by a flowering head. Later columns in Egypt were made to resemble bundles of papyrus stems, with a flowering head, which botanists call an umbel, or clusters of umbels near the top. Archaeologists believe that this tradition derives from a common technique used along the Nile by builders of early huts who are thought to have used actual papyrus tied into tight bundles as upright supports. This technique still is practiced by marsh Arabs in the Tigris and Euphrates river valleys. In the eyes of ancient Egyptians, it may be that the carved columns in temple halls evoked images of papyrus swamps, known to have been esteemed highly. Such swamps were common settings for important religious legends. For example, Horus -- the falcon-headed God of All Egypt, patron lord of the kings and son of Osiris, the King of the Blessed Dead -- was born and lived his early life in the papyrus swamp at Chemmis in the Nile Delta. Anubis, the jackal-headed god of the dead, stood guard over the entrance to papyrus swamps at the northern part of the underworld, through which no soul could pass until judged. When the dead arrived at their final resting place, it was believed that they were transformed into stars or lived in a celestial marsh similar to papyrus swamps they had left on Earth. The tradition even influenced Judaism with the story of Moses having been born in Egypt in "bullrushes" that probably were papyrus plants. At the base of columns in many Egyptian temples remain traces of wavy blue lines painted on the plaster, a depiction of water. Thus, papyrus swamps may well have been the model for these early temples, and to navigate these sacred waters, the living and dead used boats built from papyrus. At least models of the boats were left in tombs to provide the deceased with transport in the underworld. Papyrus boats were considered ideal because they had magical power to repel crocodiles, then a common Nile hazard. In a sense, the very importance of papyrus led to its decline. To protect their monopoly, pharaohs ordered papyrus plants destroyed except in special areas of cultivation under their control. With the advent of linen paper, the the papyrus market crashed, and these last surviving papyrus swamps disappeared. Farmers found the soil ideal for food crops, and with the building of drainage canals, many Nile Delta swamps dried out. A general drying of the African climate at that time hastened the decline of papyrus. As a result, to revive papyrus cultivation on the Nile today, workers had to travel to Sudan, where it grows in magnificent profusion, to collect plants. Although this giant sedge, Cyperus papyrus, has been well-known for millennia, its ecology and physiology have come to light only with the revival of interest in papyrus over the last 20 years. The largest member of the Cyperaceae, the sedge family, stems can reach 15 feet high and six inches thick, each stem topped by a graceful flowering head, the umbel. In a new shoot, the umbel remains closed until the stem has grown above its neighbors. Then it opens to reveal a large plume of fine, ray-like spikes that may bear tiny flowers typical of the sedge family. Each stem grows from a large, horizontal rhizome which spreads over the water and forms thick, floating mats. These extend from the shores of several African lakes, such as Victoria, where chunks may break loose to form large, floating islands. In past centuries, papyrus islands often blocked navigation channels, hindering the movement of explorers. Papyrus swamp habitats can be inhospitable in other ways. Because they often harbor snails and mosquitoes that transmit serious diseases, many swamps in modern times have been cleared, drained and planted in rice, sweet potatoes and maize. As a result, papyrus has been retreating. Along the Nile today, wild papyrus swamps are seen mostly in the south. In many countries, the swamps have been regarded as a resource to be used. Governments of several countries have studied whether a papyrus paper industry could be economically viable. But wood pulp is so easily produced from trees that papyrus fiber no longer is competitive. Still, papyrus swamps perform a service. They help to prevent soil erosion during heavy rains, and they take up pollutants flowing in rivers and streams, making water more suitable for irrigation or drinking. In modern-day Israel, the ecological value of papyrus swamps was made apparent in the 1950s when Israelis drained most of their swamps, exposing peat soil that began to decompose, releasing vast amounts of nitrate into the Sea of Galilee. There the nitrate fed a rich growth of algae, lowering the quality of a body of water that supplied one-third of Israel's water needs. With this example in mind, ecologists warn that attempts to canalize the Nile or to clear papyrus swamps, as has been proposed for parts of Sudan, may seriously diminish water quality. The role of papyrus as a remover of pollutants suggests that it may be useful in treating municipal sewage. Currently, sewage from many African cities receives minimal treatment before being released to natural waterways. In the Ugandan capital of Kampala, for example, sewage effluent passes through papyrus swamps before emptying into Lake Victoria. To the extent that papyrus swamps clean water passing through them, the plant may be functioning as a valuable natural resource as in the days of the pharaohs but for entirely different reasons. John J. Gaudet is a writer and free-lance ecologist who has studied the ecological role of papyrus. He has lived and worked in Africa for many years. CAPTION: Making Papyrus Paper 1 Workers cut armfuls of green stems each day and trim them into pieces about 12 inches long. These are soaked in river water until they are peeled. 2 Because the stems are triangular in cross section with flat sides, the tough skin peels easily, exposing the white pith of the inner stem. This pith is then sliced thin with a razor blade. 3 The slices are squeezed to remove excess water. 4 The strips are laid parallel, slightly overlapping, to form a sheet. More strips are laid on top at a right angle. 5 The two layers are squeezed between blotters and held under pressure until the papyrus strips dry. The natural juices from the plant glue the strips into a sheet. 6 The sheet is burnished with a fine clay powder until the surface is smooth. CAPTION: A stalk of papyrus and paper made from its sliced stem. CAPTION: Graceful papyrus plants fringe marshes in many parts of Africa. In Egypt, the valuable species was virtually exterminated before reintroduction. CAPTION: A cluster of papyrus fronds formed the hieroglyphic symbol for "Lower Egypt," the marshy region of the Nile Delta on the Mediterranean Sea. CAPTION: Hieroglyphics, developed about 5,000 years ago as one of humanity's earliest forms of writing, used stylized pictures to represent either the object or a sound associated with pronunciation of the object's name. Papyrus paper made possible easy dissemination of writing such as this example from the tomb of Siptah, pharaoh around 1200 B.C.