Sempervivum ID

I have these 3 Semervivums which I have had for a few years now but never paid much attention to the names before.
Im now getting rather obsessed with knowing the exact cultivar of each plan.

To give you an idea of scale, these are in 6inch pots.

but Im struggling with these.

 

Sorry, no idea, there are soooo many cultivars now that a lot of them look very similar, I presume you have googled them?

 

I agree. Difficult.
This site MAY help you....

http://www.sempervivumnursery.co.uk/cart/index.php?main_page=index&cPath=5&zenid=5db0042f70ba44bfbdffcfc897ca0b95

 

Many years ago the two worlds leading experts on Semps were given some pots to id. They disagreed which ones they were and argued vehemently until finally settling on some names. then the person presenting the pots admitted that all of them were the same one grown in different ways and neither expert got the correct species at all.

 

Thanks, I have tried the Sempervivum nursery website before, searched through loads without much luck. Interesting point Palustris, if the experts struggle then what hope do I have. The RHS has 1200 registered which is insane, my only hope really is that theses were brought from a garden centre so may be a common variety.

I do enjoy growing these but identifying them correctly is going to be very hard. I have others which I know the name of, but the 2 large ones are really impressive specimens so would love to ID them.