Flower with a huge red flower and long green leaves?

The amaryllis lily bears a huge Trumpet shaped flower followed by long, strap-like leaves. It grows from a bulb that is often sold as a gift or for decorating around the Christmas holidays. The bulb sends up a flower atop a long stalk that makes a fine indoor plant during the dark winter days. After it fades green foliage appears which signals the time to feed and water until the bulb replaces the energy used for flowering.