Re: The (forgotten) yuccas at Yale (ID request)
Nice to see surviving Agaves up here!
First unknown Yucca is difficult to ID. Does not appear like elata but could be a form of angustissima, harrimaniae, or glauca. Blooms would confirm ID
The last unknown Yucca might be rostrata or thompsoniana?? It's not the best photo but it sure looks like it some rupicolae series of Yucca genes in it.