凤尾兰（学名：Yucca gloriosa）又称美国波罗花，为龙舌兰科丝兰属下的一个种。

Yucca gloriosa is a species of flowering plant in the family Asparagaceae, native to the beach scrub and sandy lowlands of the southeastern USA, from the Outer Banks of Virginia and North Carolina to Florida and Alabama. It is also widely cultivated as an ornamental and reportedly has become established in the wild in Italy, Turkey, Mauritius, Réunion, Guam, the Northern Mariana Islands, Puerto Rico, Argentina and Uruguay.