When I received Dischidia pectinoides in an Ebay purchase last year I was kind of dismayed that it appeared to be growing in nothing but sphagnum.  I immediately repotted it into a soil mixture, and then after researching, I found out that moss was its preferred medium.  I then put it back into moss where it has been very happy ever since.  The photo below shows the plant in soil before I moved it back to sphagnum.