Hoya carnosa - spotted vs plain leaves?

I received some Hoya cuttings from a lady who brought them to work for me this summer.
After visiting my mother, I discovered they were the same as two of the Hoya carnosa she has (little silver spots all over the leaves), with a third having plain green leaves. So I was wondering if the ones with silver specks are perhaps a different cultivar (Like 'Grey Ghost' which shows the same characteristics as this image http://davesgarden.com/guides/pf/showimage/309577/), or are they just a variation in the species?

Thanks!
Ash

This message was edited Nov 27, 2011 2:12 PM

Wish I knew the answer, but will follow your thread with hopes of learning more. Kristi