Yucca

https://en.wikipedia.org/wiki/Yucca

 There are lots of different plant species. Here is a brief explanation about these interesting and beautiful plants from Wikipedia: Yucca. 

Yucca is a genus of perennial shrubs and trees in the family Asparagaceae, subfamily Agavoideae. Its 40–50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flowers. They are native to the hot and dry (arid) parts of the Americas and the Caribbean.

Early reports of the species were confused with the cassava (Manihot esculenta). Consequently, Linnaeus mistakenly derived the generic name from the Taíno word for the latter, yuca. The Aztecs living in Mexico since before Spanish arrival, in Nahuatl, call the local yucca species (Yucca gigantea) iczotl, which gave the Spanish izote.Izote is also used for Yucca filifera.

These plants are the Boyce Thompson Arboretum near Superior, Arizona.