You are entirely free to call your plant whatever you are comfortable with. Unless you are a botanist, names are only important to collectors & hobbyists so that when we communicate with each other we know what plant we are talking about. For this reason it is therefore useful to have an agreed name that everyone knows about. Generally folks would use the latest valid name. In this case as I know about S. 'Mason Congo' & S. masoniana I would know which plant you were talking about but I can also appreciate that S. masoniana is the correct name as it was described & published by this name (by Juan Chahinian). Mason Congo or Mason's Congo was just the trade name before it got its real name!

As I said, call it Bill, Bob or Maria if it makes you happy. LOL.

I have been collecting cacti and succulents for several years and have learned that there are "lumpers" and "splitters". Splitters tend to assign different names to small plant variations, whereas lumpers know that in reality there are wide variations in plants that share the same or almost the genetic makeup.

Sellers tend to be "splitters" and like to rename plants especially hybrids and varieties to increase their sales (who can blame them?). Whereas most botanists or people think like botanists tend to be "lumpers" knowing that there are variations.

Being a new Sans collector, I have learned that there seem to be several plants that haven't recieved botanical names. I find names like "Kenya spoonleaf" which clearly describe where the plant grows and its shape.

So the question is . . what organization is authorized to assign botanical names?

There are recognized registries... off the top of my head, I can't tell you who. The folks who explained Splitters/Lumpers over at C&S should be able to tell you.

The proof of a NEW species is at a cellular level. This discussion has been had on the Hoya forum. We seem to know some intrepid plant explorer/discoverer types over there. The retrieved tissue needs to be sent to someone with a 'library' to be compared against, to prove whether it is a species already known, or completely new. If completely new, the discoverer gets naming rights. Some of the orchidists could explain this also. Since orchids can be huge sluts, and are creating new intergenerics all the time, the same system works for them, also. Except I believe a cross needs to win an award before it gets it's 'grown up' name. All of this is second and third hand information that I am sharing so don't go around quoting me!

I'm just giving you information of places where to start asking these questions.

If you learned the old name of Crassula lycopodiodes, and prefer 'muscosa', use that. If you prefer to be more casual, use 'Watch chain'. I learned lycopodiodes, so can rattle that one off. If a plant of mine gets renamed, the new change gets input in my handwritten notes next to the other information that I have collected about that plant when someone I respect as knowledgeable tells me it has a new name. Other than that, I pretty much ignore the whole bruhaha.