Eriostemmas were attempted to be separated from hoyas at one point using some questionable facts. One of the facts used was that it did not attach itself to supports with roots from the nodal area. That is wrong...it does put out aerial roots, but not many. I had the devil of a time rooting my first Eriostemmas because I kept them too wet. I suggest that when you use the SemiHydro that you use a tall 'vessel' as they like to be 'teased' into looking for the water...(except for tarts like cv. Ruthie which will root on cement floors!!!! (not)).
Eriostemmas grow up a tree, then fall down towards the ground when they feel like it...when they hit the ground they grow along the floor/ground until they find something to climb and while on the ground, they root. This is why they are called terrestial. Laying them on top of medium (really organic stuff like you would find on the forest floor...kept 'moist' ...works really well too....
Hope this helps....
Eriostemmas...
Thank you Carol, very interesting information.