Hi Julia,
Martin Haberer is one of the great german semps-breeders and a very good semps-friend of mine :-)
we made a breeder-portrait on our homepage:
http://www.sempervivum-liste.d...
at the end of this portrait are some photos of his garden and at the bottom there is a link "Züchter-Sorten" (breeders varieties) - when you click on it you can find all the cultivars breeded by him;
he is nearly 79 years old and still travels all over the world to see foreign countrysides and rare plants; and he knows them all by botanical names; his slideshows with comments are highlights on our annual sempervivum-meetings; this year he's been in Marokko;
he is a real good fellow and likes to help newbies to start their collections with offsets from his big collection; I've got offsets of about 400 varieties from him in the first years of collecting;
Pax is a very nice variety and I really like it;
Peter