Merriam-Webster Collegiate Dictionary - joshua tree

 noun  Date: 1884 a tall branched arborescent yucca (Yucca brevifolia) of arid regions of the southwestern United States that has clustered greenish-white flowers JOSHUA  noun  Etymology: Hebrew Yehoshua‘  Date: before 12th century  1. the divinely commissioned successor of Moses and military leader of the Israelites during the conquest of Canaan according to the account in the book of ~  2. a mainly narrative book of canonical Jewish and Christian Scripture — see bible table