Hoya vangviengiensis, like Hoya carnosa, has clear sap. The foliage is lightly pubescent as can be seen in my photos below.
Hoya vangviengiensis Has Clear Sap
Vermont Hoyas
A site about growing Hoyas in the Northeastern United States
Hoya vangviengiensis, like Hoya carnosa, has clear sap. The foliage is lightly pubescent as can be seen in my photos below.