W. John Kress, Ph.D., curator and research scientist at the Smithsonian Institute, demonstrates how to capture an image of a tree leaf using his Leafsnap iPhone app.

Christmas trees are among the traditions that withstand viruses and other threats. Year after year, villages, towns and cities — including some in war-ravaged Ukraine — go the distance to ...

Hotels around the world collaborate with luxury brands for their Christmas decorations.; Some trees, like the one at Mandarin Oriental Jumeira in Dubai, have been designed by jewelers.

2,381: Farms that grew Christmas trees in Canada in 2011. 647: Christmas tree farms in Ontario in 2011. 54.4 acres: Average area of land per Christmas tree farm in Quebec in 2011. On average, Quebec ...

Rio de Janeiro in Brazil, is home to the world's tallest floating Christmas tree. The decorations represent the four seasons of the year and are lit by 3.3 million light bulbs. Image caption, ...

Some Christmas tree farms that have been holiday fixtures for decades said they won't be open this season. Aerial view over a Christmas tree farm in this undated image. STOCK PHOTO/Getty Images ...

The Origins of Christmas Trees. Records of using greenery to celebrate the holidays predate widespread use of the phrase “Christmas tree.” Rural English church records from the 15th and 16th ...

The Christmas tree outside the Rockefeller Center in N.Y.C., circa 1970. David Herman/Archive Photos/Getty Images. As the evergreens grew larger, the means of getting them from their "homes" to ...