Agave franzocinii

This is absolutely gorgeous, with almost luminously silver glaucous, yet coarsely textured leaves that are strongly recurved and twisted.  A monster plant - one of the largest agaves that can reach over 3m high and even more across.  The large silver plant in the arid part of the Princess of Wales Conservatory at Kew labelled A. americana is in fact this beauty.  Hardy ?  Maybe.  Available commercially ?  Hardly ever.  I am lucky enough to have finally tracked down a small plant of this which should be big enough to plant out in a couple of years.