Wow! Its great! It almost looks like a burgundy stapeliad, only waxy instead of hairy....aren't Hoya's related to stapelia's? Does it smell like a Stapelia? Take care, Eric
I have been testing the more uncommon Hoya species to see if they could become the next new 'IN' houseplant. Mixed results so far. Biggest draw back is relative slow growth on a home windowsill. Some really need humidity higher than is practical in a home. Many have absolutely gorgeous leaves, sadly these seldom have showy long lasting flowers. I'll let the forum know if I find a real winner. H. magillivrayii is a robust growing vine with plain green leaves, so it fails the prefect windowsill plant test, though it is certainly worth making space for in a mixed collection.
As PaphMadMan reminded us, both Hoya and Stapelia are Aesclepiads. So the expectation of foul odors is not unreasonable. Hoya breaks into several groups, the Euhoya and a few other groups are mostly pleasantly fragrant or have no odor. Some like H. macgillivrayii and closely related species have very sophisticated odors, some like H. carnosa fairly simple odors (the name carnosa is a referance to smelling like a carnation), H. subclava has a strong Concord Grape fragrance, H. davidcummingii has a buttered popcorn fragrance. Hoya lacunosa has a simple but pleasant Paperwhite Narcissus odor.
The Hoya subgenus Eriostemma (some elevate this to genus) all favor the Stapeliad cousins in that the often very large flowers tend to smell like vomit, or some very industrial ketone or ether like odor. They usually don't have a putrid odor, but they certainly are unpleasant. Bad smells, robust rangy growth habit, and the fact that many Eriostemma come from low elevation humid, wet rainforests means the whole group is pretty much a failure for the 'perfect windowsill houseplant' test. They are a collectable curiousity, for example Hoya (Eriostemma) lauterbachii will have umbels of colorful, but foul smellling, 4 inch flowers, on a 12 foot vine that needs sun, heat and humidity to get the blossoms.