Hoya merrillii is endemic to the Philippines and is named after its collector, E.D. Merrill and was originally found at low altitude on trees on Mindoro Island. Later it was found to be much more widespread than originally thought.
One of the big selling points of Hoya merrillii is the very beautiful red leaves that it gets in high light. I do highly recommend it as a worthwhile acquisition for the lovely foliage, fragrant and frequent blooms, and easy growth habits.