Beverly Works, age 12, of Fountain Valley, California, for her question:

Why does moss grow only on the north side of trees?

It is getting to be that time of year for walking through the woods, And every year, a few wanderers will take that fateful wrong turn and get lost. Before panic sets in, a lost person tries to recall sensible methods to locate the basic directions. This is when moss comes to mind  for it is supposed to grow only on the north sides of the trees. Actually, the wood mosses grow almost anywhere they choose. If we rely on them to show which is the north direction, we may never get home.

There are hundreds of moss species and most of them prefer to grow is moist shady places. If a tree stands alone, they grow better on the north side, shaded from the sun. But crowded trees shade every corner of the woods with their spreading boughs. Shade loving mosses can grow on all sides of their trunks. Besides, certain mosses enjoy a little sunshine. They prefer to grow around a lose tree. And we map find them on the north or south side, on the east or west side.