I don't need to nail anything down, thanks.
I just wanted to add the plant to my list ... I tried typing in 'Spider Lily Hymenocallis' but it was not recognized. Tried 'Spider Lily (Hymenocallis)' still not recognized. All the others are listed as Spider Lily (singular) something-or-other but...this one is a plural. Even when I typed in Spider Lilies (Hymenocallis) it was still not recognized. I had to cheat and use the 'add this plant...' easy button.
Well, thanks anyway. I have added the plant to the general listing.