Root

A root is an organ of a plant that typically lies below the surface of the soil, although it can also be aerial (growing above ground). They often can be used as a food or for medicinal purposes.

During the disaster at Arvada III, Felisa Howard learned how to use roots to treat the sick at the colony, despite not being a physician. She would also teach her granddaughter, the future Beverly Crusher, this knowledge. The knowledge benefited Beverly when she became injured on the planet Minos, where she instructed Jean-Luc Picard on how to use roots to treat her injuries. 

The Bajorans Mullibok, Keena, and Kira Nerys prepared vegetables and several roots for supper. 

The Federation colonists that lived on a planet in the Orellius system attempted to use fungi and roots to cure the deadly infections caused by insect bites that were killing their people. 

Leola root was a well known food in the Delta Quadrant, renowned as a source of vitamins and minerals. It could be made into several types of food, such as a stew, soup, and a tart.