As found in grains, it is mixed with a certain amount of vegetable fibre, covered with husks, or skin, and has the little germ or budlet of the coming plant inside it.
It has been manufactured and laid down by little cells inside their own bodies, which make up the grains; so that each particular grain of starch is surrounded by a delicate husk--the wall of the cell that made it.

This means that grains and other starch foods have to be prepared for eating by grinding and cooking.

The grinding crushes the grains into a powder so that the starch can be sifted out from the husks and coating of the grain, and the fibres which hold it together; and the cooking causes the tiny starch grain to swell and burst the cell wall, or bag, which surrounds it.
Starches as Fuel.

The starches contain no nitrogen except a mere trace in the framework of the grains or roots they grow in.

They burn very clean; that is, almost the whole of them is turned into carbon dioxid gas and water.[7] This burning quality makes the starches a capital fuel both in the body and out of it.