My Psychopsis Mariposa Green River is bark and some perlite. Has eight spikes and blooms almost year round. It fell once about 3 years ago (I have had it since 2010). No damage to the plant but broke the pot. Was told at the time that they will sulk and it did for about 10 months. I was also told that it liked a tight fit in the pot like Nobile Dens. So I kept it at the same size. Now doing great
