16-20" tall x 24-36" wide. Yucca glauca, a hallmark plant of the western Great Plains, is a spiny succulent with stiff, evergreen leaves radiating out from a central rosette. Mature Plains Yucca plants bloom in late spring with showy spikes of large ivory flowers. Later in the season, the seeds ripen in large woody pods held on upright stems. Easy-to-grow and long lived, this native species is excellent for planting with blue grama grass and other prairie wildflowers.