Yucca baccata -- Banana Yucca -- Named for the shape of its flowers, this small Yucca is native to the southwestern US and northern Mexico. It grows up to 3', with flower spikes perhaps a foot above that. The cream and purple flowers occur in spring, and the spiky foliage is blue-green. The dried fruits are preserved for winter by native Americans. Very cold hardy, to zone 5 or possibly 4, but requires dry conditions.