(ARA) - Each Christmas decorated trees, twinkling lights and familiar carols take center stage in creating a festive holiday atmosphere. Certain plants play key roles as well: church altars banked with poinsettias, mistletoe hung over doorways, and holly adorning floral arrangements. Ironically, the histories of most Christmas plants have pagan roots (pardon the pun!), some dating back to the druids in the 13th and 14th centuries. Yet over the centuries they evolved into beloved Christian symbols.

Dr. Charles Aling, professor of history at Northwestern College, St. Paul, Minn., explains that Christmas plants such as holly, ivy, mistletoe and poinsettia became Christmas favorites due in part to their bright colors and evergreen properties. "Their coloration did a lot for the drab, cold and dark time of year when other plants had died and the landscape was colorless. Both the pagans and Christians saw these plants as bringing light and color into the season."

Holly -- Holly's ability to look good in both winter and summer certainly helped its position in folklore, Aling explains. Representing immortality and seen as a good omen, holly was considered sacred by the ancient Romans and used as a gift during the festival of Saturnalia. Holly was brought into homes when winter began to shelter the elves and faeries.

During the early years of Christianity in Rome, many Christians continued to deck their homes with holly to avoid detection and persecution. Gradually, holly became a Christmas symbol as Christianity became the dominant religion. Because the holly leaf has sharp, pointy edges, Christians see the holly representing Jesus' crown of thorns and the red berries representing the blood He shed on the cross. Ivy -- Aside from the familiar carol, "The Holly and the Ivy," the ivy vine doesn't have quite the Christmas tradition as mistletoe and holly, Aling says.

It was associated with Bacchus the Roman god and thought to bring good luck, fun and ecstatic happiness. Growing the plant on the outside walls of a house was believed to be a deterrent against misfortune. However, if it died, it was thought that financial trouble was approaching. Like evergreens, ivy was also seen as a symbol of eternal life.

Because ivy symbolized prosperity and charity, it became associated with Christmas, a time to celebrate the rich rewards of life yet remember the less fortunate. Christian symbolists also consider the ivy's need to cling to a support emblematic of man's need for divine support, explains Aling.

Mistletoe -- Legend explains that the tears of Scandinavian goddess Frigga saved her son after he was shot with an arrow made of mistletoe. When she ordered mistletoe never again be used to harm others, she made it a symbol of peace and love. It was also hung over doorways to ward off evil and bring happiness, health and good luck, and kissing under the mistletoe was thought to increase the possibility of marriage in the upcoming year.

When Christianity took a foothold in northern Europe, mistletoe was one of the pagan casualties. For centuries it was forbidden on Christian altars. Eventually, mistletoe found its way back into acceptance when the Victorians revived the ancient ritual of kissing under the mistletoe as a sign of love, romance and good luck.

Poinsettias -- "While most Christmas plants date back several hundred years to Europe and the Mediterranean," Aling points out, "the poinsettia is a relatively recent Christmas symbol based in the Western world." Native to Mexico and cultivated by the Aztec Indians, the poinsettia is named after Joel Roberts Poinsett, first U.S. Ambassador to Mexico, who imported it from Mexico in 1828. After the Spanish conquest and the introduction of Christianity, the poinsettia found a place in Christmas rituals.

The legend of the poinsettia tells of a poor village boy in Mexico who wanted to give the Holy Child a gift, but had no money. In desperation, he picked some weeds on his way to church to leave as his gift. He prayed to God to help him show his love and God answered by turning the weeds into a beautiful star-shaped flower with bright red leaves. The poinsettia has been a Christmas symbol ever since signifying how Jesus meets the needs of His believers.

Even though most Christmas plants are short-lived, basic care helps them last through the holiday season.

"Holly is actually a shade shrub that is quite plentiful in England. The shrub should be planted in the spring," explains Dr. Jerry Beilby, professor of biology at Northwestern College. "Cut holly lasts longer indoors if treated like cut flowers, placed in cool water, and kept away from excessive heat."

Ivy is more of an English Christmas green than an American one, he says. "It's a very popular houseplant in the United States since it's relatively easy to grow. It takes low water, either direct or indirect sun and even thrives in the shade."

Mistletoe is actually a parasite that feeds off trees and shrubs, Beilby says. "Plants bloom in the summer and produce white berries during the winter. Mistletoe is often hung upside down and dried during the holidays." The berries are poisonous, so keep the sprigs out of the reach of children. Many commercial firms now market mistletoe with artificial berries for safety.

A poinsettia can last for weeks beyond the holidays when placed in indirect sunlight at least six hours a day," he explains. "Keep it away from cold drafts and excessive heat. Water when it feels dry, and after the blooming season use an all-purpose fertilizer once a month."

Beilby adds that the belief that poinsettias are poisonous is a misconception. Scientific evidence of the plant's safety is ample and well documented. Poinsettias are actually helpful in removing pollutants from indoor air.