Family : Acoraceae
Acorus calamus (sweet flag), occurs
in the wetlands of North America and from India to Indonesia in
the Old World. It is plentiful in the marshy tracts of Kashmir,
Himachal Pradesh and in Manipur and Naga Hills. It is cultivated
in some parts of Karnataka.
Sweet flag is a semi-acquatic, perennial,
aromatic herb with flat, leaf-like stems and sword-like leaves at
the base. It grows to a height of about 1.5m and bears a 5 to 10
cm long fleshy cylindrical structure halfway to the top. The creeping
rhizomes are jointed, vertically compressed, pale to dark brown
in colour. Tiny yellowish brown flowers are embedded in a spadix.
Berries are green, angular and 1-3 seeded.
Sweet flag is grown in clayey loams
and light alluvial soils. The growing tops of the previous year’s
crops are planted 30 cm apart. The crop is ready for harvest within
an year. The plants are dug out, fibrous roots are removed and the
rhizomes are cut into pieces, washed and dried in the sun.
Aroma and flavour
It yields around 1.5-3.5% volatile
oil known as calamus oil. The important constituents of this oil
are asarone and its b-isomer.
Medicinal and Other use
The dried rhizomes constitute the
drug ‘calamus’ of commerce. In Ayurved the rhizomes are considered
to possess anti-spasmodic, carminative and anti-helmintic properties.
Extracts of whole plants of sweet flag have been employed for medical
purposes since the time of ancient Greece, and its leaves have provided
floor covering as well. American Indians had so many medicinal used
for the rhizomes and roots. Physicians used it for stomach cramps
and gas and as a tonic and stimulant. Its root is used in india
to treat toothache, fever and menstrual problems.