It's the result of streamlining, Lynn. If information is presented in the top line of the entry, it isn't repeated in the body of the entry. All of the name information is still there if you click on "Edit plant name."
I don't know whether you could search by series within the Sempervivum Database before, but you can run a general search for the Sempervivum series. Here's what I found when I searched for "sempervivum lord of the rings":
http://garden.org/plants/searc...