I've been intrigued with the distribution of this species of yucca in the past several weeks since I learned to distinguish it from twist-leaf. Here I photographed a small clone of the species on a roadside in extreme southern Mills County (CR 423, west of US 183) but I saw the species commonly on gravelly/rocky limestone terrain throughout the county in my wanderings on this date. No sign of twist-leaf yucca in that area.