Milk comes from a cow, not a plant.
Many plants produce a 'milk' when they are damaged. It is basically the sap of the plant. These tend to be fairly succulent and most (if not all) are edible. Milkweed and Dandilions are two of the most common.
Soy milk is not milk, it is the actual beans ground up and suspended in water.
An ovary is the part of the plant an apple comes from.
It is a SEEDof the plant.
Banana is the fruit of a plant
A beet is a root plant.
It is a plant in it's own right, not part of anything else.
kiwi comes from the bud of the plant
Caraway is the seed of the caraway plant.
stem
Root.
the flower
stems
The root.