Note: Do not rely on this information. It is very old.
Yucca, a genus of Liliaceae, occurring in the Southern United States, Mexico, and Central America. They are commonly arborescent, having a pericycle in which new fibro-vascular bundles originate in old stems. Their leaves are in a crown, rigid linear-lanceolate, and acute, from which they have acquired the popular name of Adam's Needle.