Hello Tim,

Your specimen is much bigger, than any of those I have, the longer and warmer growing season at his place, makes a big difference.

It's interesting that the leaves are plicate, very much like the Yucca recurvifolia we have here in Denmark.

My theory that Yucca gloriosa is a result of a hybrid of Yucca aloifolia x filamentosa and the Yucca recurvifolia is a hybrid of either Yucca aloifolia x flaccida or Yucca gloriosa x flaccida might be true :-)
I can't wait to read the article about the origin of Yucca gloriosa, written by a University of Georgia Ph.D Candidate which will be published soon. His work will hopefully bring more valuable information about Yucca gloriosa, and probably also new questions as usual :-)

Have a nice day

Benny