How do most saprophytic plants actually obtain their food?

1. A saprophyte is a plant without chlorophyll that gets its food from dead matter. 2. Most saprophytes do not directly digest that dead matter themselves. 3. Instead they parasitise fungi that digest dead matter, or they are mycorrhizal. 4. Either way they end up obtaining photosynthate from a fungus that derived it from its host. 5. Direct digestion is the obvious guess and is exactly what the wording rules out, so it is the trap here. 6. Fixing carbon dioxide is impossible for them because they lack chlorophyll, and saprophytic plants are uncommon with only a few species described. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 31 "Soil and Plant Nutrition", section 31.3 Nutritional Adaptations of Plants_