Hoya towutiensis is a type of plant that's part of a larger group called the Hoya caudata Hook.f. complex, kind of like a plant family. They all have similar features, such as pointy crowns on their flowers, long bits sticking out of the flower part, and these pollen things with little wing-like parts (Rahayu & Rodda, 2019). Think of it like a family of plants that look alike.
Now, here's the interesting part. Hoya towutiensis is most like its cousin, H. sumatrana. But you can tell them apart by looking at their flowers. When Hoya towutiensis is blooming, its flowers are a bit smaller and cream-colored. In comparison, Hoya caudata's flowers are bigger, and they can be white-pinkish or even cream-pink. Plus, if you peek inside, you'll see the middle part is different in shape and size. So, in simple terms, they're like plant cousins with slightly different-looking flowers.
NOTE: This plant used to go by the name Hoya caudata (silver).