Arrowroot

Arrowroot is a starch obtained from the roots and tubers of various tropical plants. One baking textbook calls it a highly nutritious farinaceous starch from West Indian plants, and the best-known source is the rhizome of Maranta arundinacea, a plant whose starchy root is the basis of the powder sold under the name.

In the kitchen it is used to thicken delicate soups, sauces, puddings and custards, and it also finds a place in pastries. Plant references describe the rhizome as a source of high quality starch for thickening sauces and soups.

As with other starches, it is usually stirred into a little cold liquid first to prevent lumps, then cooked into the hot mixture until it thickens. Because it comes from a root rather than a grain, it is a handy alternative to wheat flour as a thickener.