The rhizome of Geranium maculatum.

Characters. - Horizontal, cylindrical, two to three inches (5 to 7 centimetres) long; half an inch (12 millimetres) or less thick; tuberculated, longitudinally wrinkled, dark brown; fracture short pale red-brown; bark thin; wood-wedges yellowish, small, forming a circle near the cambium line; medullary rays broad; central pith large; rootlets thin, fragile; inodorous; taste astringent.

Composition. - It contains a considerable amount of tannic and gallic acids. Uses. - It is a mild and not disagreeable astringent, especially useful for children. It is used internally for diarrhoea, and is employed also as an astringent gargle in sore-throat and as an injection in gonorrhoea and gleet