If you have a good supplier, don't change. Manolyn looks looks like several Florida plants, in Calif. that are touchy to grow, (getting rust). I would stick with Karole, S. guinenses is a name that is not used any more in the trade. I think it may apply to the Florida Sansevieria? S. Tenzen grows like it and looks like it, but does not rust up, this plant was found and named by Hermine Stover.
Siam Silver may be the same plant, named changed in Thailand. I have all three. As a price guide the single head about 10" tall should sell between $18.00 and $25.00 no more. Norma

Thanks Norma. This is definitely good information to have, particularly the info about the rust. I did get my S. SCHWEINFURTHII from Glassworks and it was an absolutely beautiful plant (and really large!). I noticed Karole is away until mid June and I have a few more plants ordered from her as well as a 'wish list' for Manolyn. I'll have to include the others as alternatives. Will also check out a few of the other sites I've seen mentioned here!

I grew mine from Rhizomes given to me for the Huntington Gardens. This was early Sept. and I had a heated location. They sold them the end of Sept. for $25.00
I had given them back to the Huntington for sale. They were not my plants. I purchased one in Seattle for $18.00.
I purchased my first one 30 yrs. ago. I know more now how to keep it alive. It grows very dry, in extremely well draining soil. I also grow it crowded in a small container. I hope this information will be of help. I live in a hot dry valley and use no Peat Moss. Norma