The term arrowroot can be applied to several species of plants, including purple arrowroot (Canna edulis), East Indian arrowroot (Curcuma angustifolia), and Brazilian arrowroot, also known as tapioca. However, the “true” arrowroot is from the plant Marantha arundinacea, which is native to the West Indies. Its name came from the Arawaks, the native people of that region. They used mashed pieces of the root to heal people wounded with poisoned arrows, hence the name "arrowroot". There are several varieties of this arrowroot that are categorized as either white or red. The latter is thought to be the superior variety. Arrowroot is predominantly grown in Brazil and Thailand.

Arrowroot plants are tropical and perennial and are found mainly in warm, swampy areas. The plant’s stalk has numerous large green leaves and can reach six feet tall. It produces white flowers on the top of the stalk. The plants are grown for half a year to a year before they are harvested. The underground stems of the plant, known as rhizomes, are edible.

The long and pointed rhizome from the Marantha arundinacea arrowroot plant, as well as the other arrowroot plants discussed above, can be eaten, however it may be too fibrous for some tastes. The flavor is said to be mild and starchy. The rhizome can be prepared in the same way as other root vegetables like potatoes. It can be boiled, roasted, baked, or fried.

The main use of arrowroot is as a thickening agent for a variety of sauces, pie fillings, and puddings. The rhizomes are peeled, grated, and soaked in water. The water turns milky white and this liquid is dried down to make arrowroot starch, also known as arrowroot flour. This starch is a white powder similar in appearance and texture to cornstarch. Arrowroot powder is generally first mixed with a bit of cold liquid before adding it to the dish that will be thickened to prevent lumps.

Arrowroot starch has some benefits and downsides when compared to other thickening agents. First, it is a stronger thickening agent than cornstarch or flour. Two teaspoons of arrowroot has the thickening power of one tablespoon of cornstarch or two tablespoons of flour. Second, arrowroot thickens liquids at a lower temperature than cornstarch or flour. This makes arrowroot ideal to thicken dishes with eggs, such as custards, that do not handle high temperatures well. Third, arrowroot starch turns clear when it is cooked, making it useful for thickening fruit gels or other clear sauces. Fourth, arrowroot has no flavor. However, the major downside of arrowroot is that dishes thickened with it do not hold their consistency as long as dishes thickened with other agents. Therefore, dishes with arrowroot should be served as soon as possible to ensure that they are thick. Also, arrowroot tends to lose its thickening power as it ages, so it should be used within a couple of months.

Arrowroot starch is very easy to digest and biscuits made from arrowroot are often sold for infants. The starch is also a good choice for those who are allergic to wheat and cannot thicken dishes with flour. Besides being used as a thickener, the powder is also used as baby powder.