This year's Earth Day on April 22 celebrates trees, with the ambitious goal of planting 7.8 billion—one for every person on the planet—by 2020. (Full story:
  1. El Arbol del Tule, Oaxaca, Mexico
    Like a living cathedral, the tree known as El Arbol del Tule, outside Oaxaca, Mexico, dwarfs the Church of the Assumption. The tree’s 50-foot (15-meter) diameter trunk supports branches the length of two tennis courts. In 1992, to mitigate the damage caused by car exhaust and a falling water table, the government rerouted the Pan-American Highway and approved a grant to dig a well for the tree. (Photo by Diane Cook and Len Jenshel, National Geographic)
  2. Friendship Trees, Yoshino Cherry, National Mall and Memorial Parks, Tidal Basin, Washington, D.C.
    Eliza Ruhamah Scidmore, a writer, photographer, and editor for National Geographic in its early days, visited Japan for the first time in 1885 and was enchanted by the blooming cherry trees that edged the Sumida River in Tokyo. After returning home, she petitioned officials in Washington, D.C., to plant trees like those she’d seen in Japan in the barren areas around the Capitol. (Photo by Diane Cook and Len Jenshel, National Geographic)
  3. Luna, Redwood, Redwood Forest, Stafford, California
    The biography of the thousand-year-old coastal redwood known as Luna in Northern California’s Humboldt County includes a chapter in which the life of the tree is conjoined with that of activist Julia Butterfly Hill. In 1997, Hill climbed the tree, threatened by logging operations of the Pacific Lumber Company, and stayed there for more than two years. (Photo by Diane Cook and Len Jenshel, National Geographic)
  4. Tanzlinde, Linden, Peesten, Germany
    In Germany, the linden is a tree for lovers; in Scandinavia, a favorite haunt of elves, and after dipping his madeleine in tea made from linden flowers, Marcel Proust’s protagonist, Charles Swann, fell into a remembrance of things past. In many parts of Europe, it was believed that only the truth could be spoken under its branches, and so judicial hearings were held under its aegis. (Photo by Diane Cook and Len Jenshel, National Geographic)
  5. Discovery Tree, Sequoia, Calaveras Big Trees State Park, California
    In 1852, a hunter chasing a wounded bear near one of the mining camps that mushroomed during the gold rush stumbled on a tree more than 280 feet tall. The find sparked a “green rush,” as speculators swooped in to commercialize the discovery. They stripped the bark and sent it to be exhibited in San Francisco and New York. A year later, the sequoia itself was cut down. The stump was used as a platform for tea dances. (Photo by Diane Cook and Len Jenshel, National Geographic)
  6. Pando, Quaking Aspen, Fish Lake National Forest, Utah
    Though it sounds like the creation of a sci-fi writer, the Pando clone, made up of 47,000 tree trunks, covering 106 acres, and weighing in excess of 13 million pounds, is actually a single organism—a quaking aspen. The clone starts as a single seed and spreads (pando is Latin for “I spread”) by sending up shoots from its expanding root system. Each trunk is genetically identical. (Photo by Diane Cook and Len Jenshel, National Geographic)
  7. Walt Whitman Civil War Witness Trees, Catalpa, Fredericksburg and Spotsylvania National Military Park, Fredericksburg, Virginia
    In December 1862, after seeing his brother’s name on a list of the wounded at Fredericksburg, Virginia, Walt Whitman rushed from his home in Brooklyn to search hospitals near the site of one of the Civil War’s deadliest battles, and confronted the ghastly reality of war. At Chatham Manor, a makeshift field hospital, he saw amputated arms and legs tossed out of a window into a growing pile under two catalpa trees. (Photo by Diane Cook and Len Jenshel, National Geographic)
  8. Bunut Bolong, Banyan, Asahduren Village, Bali, Indonesia
    The banyan tree is one of the most venerated trees in Asia. In Hindu mythology, it is the tree that fulfills wishes. The Bodhi tree, which Buddha sat under for seven days to attain enlightenment, was also a type of banyan. This example, known as the Bonut Bolong, grows on a steep hillside in Bali, Indonesia. (Photo by Diane Cook and Len Jenshel, National Geographic)
  9. Sacred Tree Shrine, Neem, Sardar Sweet Shop, Bhojubeer District, Varanasi, Uttar Pradesh, India
    It began with a cart that sold sweets parked in Varanasi under a Neem tree—a species sacred in India. Each day, Deepak Tadaw and his family would worship the tree, and each day, business incrementally improved. Because a Hindu would never chop down a Neem tree, which is the embodiment of Shitala, the goddess of good fortune, the family built their sweet shop around the tree. (Photo by Diane Cook and Len Jenshel, National Geographic)
  10. Wedding Oak, Live Oak, San Saba, Texas
    The romantic lore of the tree just outside the town of San Saba, Texas, known as the Wedding Oak, began, it is said, with Native Americans who held meetings, ceremonies, and weddings under its shade, but the association of trees with love began long before. In Greek mythology, Orpheus, who reclaimed his dearest Eurydice from the underworld, played her a love song on his lyre, causing an elm grove to grow on the spot. (Photo by Diane Cook and Len Jenshel, National Geographic)