You can eat them in the fiddlehead stage, despair over proper identification, and grow your own from spores or other reproductive techniques. Ferns make good houseplants, but some need lots of coddling--regular watering especially. Most can survive if the indoor humidity hovers around 40 or 50 percent, the temperature between 60 and 70, and the light is strong and indirect--North or East windows are best. Outdoor cultivation is more limited: only a few can endure winter temperatures. This enthusiastic, nicely illustrated survey covers the natural history and habitats of ferns as well as their household possibilities. From Bostons to Staghorns, a treat for aficionados.