Not All Plants Are the Same
All plants need roots to take in water. They get water from the rain for ponds and all the other water sources. Sometimes in the olden days people they took water from ponds to drink and clean.
Not all fruit is edible. You can not eat pine cones and poison berries but you can eat blue berries and raspberries. Sometimes you can die from poison berries. You should not eat berries you don't know for sure what type it is.
Some plants grow again by spreding seeds because the wind takes them and some grow from people planting seeds or cuts of plants.