As I've read around on various internet sites and I've often seen Hoya referred to "clones." "This carnosa clone" or "this clone of Hoya obsura" are examples of how I've seen them described. Does anyone know what this means? Is it just another way to say it's a propagated plant? Or is it more science-y than that?

All it means is meristem propagation (i.e. taking a cutting and rooting it and growing a new plant from the cutting). Cloning is different than growing from seed.

That's kind of anticlimactic. I was expecting something with a lab and Petri dishes. Very science-y. So we just make a clone every time we propagate a plant by stem cuttings

Basically yes. You can tissue culture clones from the plant meristem (in orchid-speak these are mericlones) but the most common clones are just vegetative propagation

Has anyone ever had a Hoya set seed? I have been growing them since I was a teenager (back in the last century ) and I have never seen Hoya seeds.

Some plants (Opuntia comes to mind) continue to flower but have gotten so good at vegetative reproduction, they no longer set seed. Are Hoya in the same category? Are there still Hoya hybrids being developed from seed grown plants?

There is such a thing as genetic drift... The farther a clone gets from the original parent, the bigger the chance for 'abnormalities' and new characteristics.

No I have never even heard of it!

Susan from KOKO ranch Hoya told me that her hybrid 'Crystal' came from a seed. It's actually her daughter Crystal's hybrid as she did it for a school project. It's a variety of carnosa and a variety of pubicalyx but I don't recall which of each. Anyway, she said her daughter tracked the moth that pollinated the plant and saw through the growth from start to finish.

I have seen Hoya mathilde and Hoya Chouke Referred to as "sister Hoya" as they came from the seed pod, a product of Hoya Serpens and Hoya carnosa. Mathilde has small round leaves like Serpens and Chouke has small pointed leaves that look like smaller carnosa leaves.

I've had a few Hoya plants produce seed pods over the years but I never collected the seed.

So cool, Lin! They look like green beans

I have never seen Hoya seed pods! They look like Asclepia and Stapelia seed pods so had to go look it up. All belong to the sub-family Asclepiadaceae. Who would have guessed?

But thinking about it, the flowers are also similar, especially Hoya and Asclepia. Stapelia are just bigger single flower versions.

Adrienne, thank for the background info on 'Crystal'. I just got one and indeed it looks like a carnosa/pubacalix!