Arbor DayyoudaoicibaDictYouDict[Arbor Day 词源字典]
the day set aside for the planting of trees, first celebrated 1872 in Nebraska, the brainchild of U.S. agriculturalist and journalist J. Sterling Morton (1832-1902). From Latin arbor "tree," which is of unknown origin.[Arbor Day etymology, Arbor Day origin, 英语词源]