Parenchyma cells are the most abundant kinds of cells found in plant tissues. They are the least specialized of all the cells. They can divide and give rise to more specialized types of cells, therefore, they can be expected to be found inside all root, stem, and leaf tissues throughout the plant.
Plants grow from areas called meristems. Parenchyma cells would be very common in this area because, as they divide, they are giving rise to root tissues and root hair tissues. The specialization that has occurred is so that there is a large supply of water entering the plant.
Fruits are also a modification of parenchyma cells. Apples, peaches, bananas, and oranges are all made of parenchyma cells. The tissues in leaves that would have parenchyma cells include the spongy layer and the palisade layer.
Parenchyma cells are the most abundant kinds of cells found in plants.