Manger des pissenlits par la racine, literally “to eat dandelions from its roots”, means to be dead. The expression dates back to the 19th century. It is an allusion to plants, which, like the dandelions, grow easily on freshly plowed soil. More precisely, the dandelions would grow where someone has been buried and then spread on the grave, “feeding” the deceased person.
French with Valerie 