WordNet sense 1 (yucca of southern United States having a clump of basal grasslike leaves and a central stalk with a terminal raceme of small whitish flowers):

Yucca smalliana

WordNet sense 2 (yucca of west central United States having a clump of basal grasslike leaves and a central stalk with a terminal raceme of small whitish flowers):

Yucca glauca

WordNet sense 3 (stemless plant with tufts of grasslike leaves and erect panicle of minute creamy white flowers; southwestern United States and Mexico):

Nolina microcarpa

WordNet sense 4 (plant of western North America having woody rhizomes and tufts of stiff grasslike basal leaves and spikes of creamy white flowers):

squaw grass, Xerophyllum tenax