This is a tropical succulent requiring more year-round warmth than most of our collection.  Nevertheless, its stiff, cardboard-like leaves and seeming indifference to mild drought imply the CAM metabolism found in the more succulent hoyas.  In this case, the leaves are only about 1 cm in diameter, dime-like and orbicular except for the elegantly attenuate tip.  They are arranged in orderly opposite pairs and bear silvery trichomes in a cryptic pattern resembling lichen encrusted bark.  The species is native to Peninsular Malaysia where it grows as an epiphyte.  Rooted cuts of HBG 95217, a plant from UC Davis without further data.  $10.