lignum vitae (lĬg´nəm vī´tē) [Lat.,=wood of life], tropical American evergreen tree of the genus Guaiacum. The hard, dense, and extremely durable wood, obtained chiefly from G. officinale and G. sanctum, is used for ship construction, butcher blocks, and other articles requiring strength and hardness. The trees are cultivated to some extent in Florida and California for ornament. They also yield guaiacum, a gum resin used in certain drugs. Various other hardwoods of Australasia (e.g., the acacia and eucalyptus) are also called lignum vitae. Lignum vitae is classified in several orders in the division Magnoliophyta, class Magnoliopsida, order Sapindales, family Zygophyllaceae.