The unpeeled, dried rhizome of acorus calamus Linne.
HABITAT.--United States, Europe, Western and Southern Asia, including
India and Japan.
PROPERTIES.--The leaves as well as the root have an aromatic odor; but
the root only is employed. It should be collected late in the autumn, or
in the early spring. After removal from the ground, the roots are
washed, freed from their fibers, and dried with moderate heat. By drying
they lose nearly one-half their diameter, but are improved in odor and
taste.
CONSTITUENTS.--Acorin, a liquid, yellow glucoside, having a bitter
taste; a volatile oil; calamine; choline.
DOSE.--Horses and cattle, 1 to 2 ozs.; sheep and pigs, 1 to 3 drs.;
dogs, 15 grs to 1 dr.