Well, if you search for exactly "Sempervivum" it will send you over to the Browse by Genus list.
But if you search for more than that, then it will search for the text you search for. I think it's a pretty good system and I don't think it'll confuse people.
Basically, the rule of thumb is: if you want to see a list, use the "Browse" page. If you want to search for a specific plant, use the search engine.
