Plants that provide energy in the form of nutrient molecules are known as

This is in the context of a food chain; plants that provide energy are called "producers" whereas the animals or other organisms that eat plants are called "primary consumers". When another organism eats a primary consumer then that is called a secondary consumer. Lastly, then these organisms die, the bacteria and other microorganisms in the soil will decompose the bodies there called decomposers.

Succulents are the type of plant. like a cactus.