Chris this is how S. arachnoideum ssp. tomentosum (laggeri) should look like:
http://www.sempervivum-liste.d...
both plants at SMG and Perennial Obsession don't look like the real plant;
in older archives we found a S. 'Laggeri' - a cultivar named Laggeri which should be breeded by Sandy Mac Pherson (like SMG write at their plant)?!? - but also this cultivar should be a S. arachnoideum ssp. tomentosum-cultivar and it doesn't look like one;
S. arachnoideum ssp. tomentosum has a lot of web and never lose it around the year!!
Peter