Close relatives, but as difficult as platycaulis is to grow well, it is a walk in the park compared to Hoya medinillifolia.
Hoya medinillifolia and Hoya platycaulis
Vermont Hoyas
A site about growing Hoyas in the Northeastern United States
Close relatives, but as difficult as platycaulis is to grow well, it is a walk in the park compared to Hoya medinillifolia.