Robert Kazimowicz, age 10, of St. Catharines, Ontario, Canada, for his question:

What is the name of the world's tallest tree?

In tropical jungles, many trees stand 150 feet tall. In parts of Australia and Asia there are even taller ones. But most experts agree that the loftiest giant of them all is a California redwood. It also happens to be one of the world's most beautiful trees. In the redwood forests of California, many specimens lift their pointed crowns 200 and often 275 feet above the ground. There are trees this tall in other parts of the world, but the great redwood called sempervirens can do even better.

A few years ago, a mighty giant was found in an almost forgotten grove. It grew in Humboldt County, the redwood territory of California. It stands 368.6 feet high, which makes it the tallest tree that has been measured accurately by experts. There may be even taller trees in the world, but so far they have not been found. Nobody thought to give the reigning champ a personal name of its own    but it is a California redwood tree.