Why Is It Called "Lucky" Bamboo?

Along with its ease of growth, Lucky Bamboo has long been associated with the Eastern practice of Feng Shui - or the bringing of natural elements of water, fire, earth, wood and metal into balance within the environment. Lucky Bamboo is believed to be an ideal example of the thriving wood and water element, with the addition of a red ribbon sometimes tied around the stalks - which is believed to "fire" the positive flow of energy or chi in the room.
The number of stalks also has meaning : three stalks for happiness; five stalks for wealth; six stalks for health. Four stalks, however, are always avoided since the word "four" in Chinese sounds too similar to the Chinese word for "death"!

(Info. pulled from http://www.chiff.com/a/lucky-bamboo.htm)