TD,

I don't know why hoya rigida does this but it does!!!! Mine has done it for years and those little growths always seem to fall off sooner or later.

If you look back at some of my rigida pics on GW you'll notice the same little spirals on many of my plants leaves.

Oh good! I thought I had exposed it to too much gamma radiation or something! Lol!

That's pretty neat! The first photo makes me think of a root but the second is not root like at all. I wonder if this little growth has been identified? I will have to keep a close eye on my Hoya rigida.
I find that my Hoya meliflua develops little mounds of crystal like slivers from this area of it's leaves but I have not seen this in my other Hoyas.

Mike