Dischidia is a sessile pitcher plant similar to nepenthes & sarracenia. It differs from nepenthes and sarracenia because it's pitcher is not having lids and the absence of insect trapping as it is a myrmecophilic plant and an epiphyte.
Santalum album is a partial root parasite because it photosynthesizes its own food, but taps the roots of other species for water and inorganic nutrients. So it depends only partially on the host.