True, This is because they they reproduced itself by spores called Sori so therefore they do grow underground stem
The energy-rich compound needed by organism is : Carbohydrates
Carbohydrates consist of the combination of the existing Carbon, Hydrogen, and Oxygen alone.
For human, The source of carbohydrates could be found in almost every food, but the huge amount could be found in rice, potato, corn, cassava, oatmeal, etc
hope this helps