There are several speces that look very similar to a hobbiest's eye. I'm sure there are miniscule differences that an expert can see, and often times, the biggest difference is in the flowers. And it's not necessarily about color as much as about structure. With my hobbiest's eye, I see the big picture and little of the minutia. (With my old-lady eyes, I see even LESS minutia, LOL!) But when an expert can SHOW me, side-by-side, the differences, I can see it. But by the next time the subject comes up again, I couldn't tell you what the differences were because it's really not all that important to me. I know what I like and I grow it. If it's name is Mary and one that looks almost the same is Jane, I don't really care - I figure they could be sisters and I'll keep their names straight and most likely, keep them both in my collection!

Now, another thing I'll point out is how different clones must affect the difficulty of truly knowing if this one is actually a different species or just another clone of that species. Macrophylla is a good example of that. There is a wide-leaved clone (which is the one I have) and a narrower-leaved clone (which is a little more common). Most of the variegates seem to be from the narrower-leaved clone. And look at all the different sports and cultivars, clones, whatever, that have come from lacunosa. I think as DNA testing becomes more affordable and prevalent in plant research that we'll see that there are fewer species than we think. I bet there will be a shift in how they're named - probably something like Genus specie then a number that identifies where it grows or maybe even the name of the place, something that distinguishes one clone from another clone.

Denise in Omaha

It really amazes me how little scientific research into hoya there is. I'm sure there will be lots of lumping one day. Also into the naming of species. The Genus Hoya expressed it so politely when it stated most species have been published in hobbiest journals with out peer review. i.e. H. krohniana.