Maranta. Arrow-root. (Not officinal.) [Officinal in U. S. P.] Fecula of the tuber of Maranta arundinacea (arrow-root); Lin. Syst., Monandria monogynia; native of the West Indies.

Description. A white powder, tasteless and inodorous.

Prop. & Comp. It consists of pure starch. Under the microscope the form of the granules is ovate, oblong, or irregularly convex, with very fine rings, and a circular hilum, often cracked in a stellate or linear manner; their size varies from the 800th to 2000th part of an inch; the greater number are small.

Therapeutics. Demulcent; chiefly employed as an article of diet for invalids.

Dose. Ad libitum.

Adulteration. Potato starch, distinguishable under the microscope by having much larger grains than arrow-root, and by the concentric rings being strongly marked.